The high sensitivity of gravitational wave detection provides a new way to explore the universe. Gravitational wave detection is a field of modern physics that has gained significant importance. The primary focus of space gravitational wave detection is to capture gravitational wave signals in the frequency range of 0.1 mHz to 1 Hz, which are mainly released by double compact star systems and astronomical events such as the merger of double black hole celestial bodies with a maximum mass ratio. This detection method complements ground-based gravitational wave and primary gravitational wave detection techniques. Space gravitational wave detection primarily relies on the establishment of a high-precision space inertial reference load ultra-stable platform across multiple satellites and high-precision inter-satellite laser interferometry technology as its core, including the tow-free control technology, ultra-high-precision inter-satellite laser interferometry technology, ultra-high sensitivity inertial sensing technology, precision formation technology, micro-new micro-push technology, and more. The laser source noise of spaceborne laser systems directly affects the sensitivity of ultra-high precision inter-satellite laser interferometry technology. Therefore, it is necessary to suppress laser intensity noise. Low noise laser source is essential to build a large-scale laser interferometer device for both space and ground-based gravitational wave detection. With suppressing the noise of the laser source by photoelectric feedback, the sensitivity of the gravitational wave detection device is improved. In the photoelectric feedback loop, the signal detected by the photodetector is first subtracted from the signal of voltage reference source, after passing through the proportional integral differentiator, it is then fed back to the pump photocurrent to suppress the noise of the laser source. During the feedback process, the photoelectric detection is the first stage to acquire the signal, the noise level of the photodetector will directly affect the performance of subsequent feedback loop. To improve the accuracy of the detection and level of the noise suppressing, the electronic noise of the photodetector must be restrained while the detection range must be expanded. To deal with the problems mentioned above, the photodetector with low noise is finally designed by choosing low noise voltage reference chip, low dark current photodiode, using low temperature drift factor element, designing transimpedance amplifiers circuit together with precise temperature controlling and electromagnetic shielding. Photodiodes need to be loaded with appropriate reverse bias for photoelectric conversion. The voltage stability of the reverse bias will directly affect the stability of photoelectric conversion in the photodiode, thus affecting the electronic noise of the photoelectric detection system. At the same time, the electronic noise of the photodetector is measured using a low noise power supply without a light source, and the electronic noise of the detector is tested using a high-precision multimeter. The performance of the designed photodetector is evaluated with the low frequency intensity noise evaluation system. The results show that the electronic noise spectral density of the detector is less than 1.649×10^-5 V/Hz^1/2,1.649×10^-5 V/Hz^1/2 at 0.1 mHz,6.95×10^-6 V/Hz^1/2 at 1 mHz,7.07×10^-8 V/Hz^1/2 at 1 Hz at the frequency of the space gravitational wave band. The gain of the photodetector is 40 dB with 8 mW laser injecting into the photodiode. The performance of the designed photodetector satisfies the requirement of laser noise suppressing for gravitational wave detection. In order to characterize the relative intensity noise of a laser light source and address the need for noise suppression in space gravitational wave detection, a system is developed to evaluate laser intensity noise for this purpose. This system includes a key device in the feedback loop for suppressing relative intensity noise within the frequency band of space gravitational wave detection: a low noise photodetector. Such photodetector plays a crucial role in the devices of laser noise suppressing for gravitational wave detection.