A new continuous variable phase detection platform was built. In the proposed platform, electro-optic modulator was used as the transmitter to produce continuous phase shift, homodyne detection circuit was used as the receiver to measure the phase of the light field, and high performance NI data acquisition card PCI6111E was used to control the entire system.The LabVIEW program technologies, including PID control, DAQmx data acquisition and triangle fit, which can reduce system development time, were used to improve the programming efficiency. The feasibility of the continuous variable phase detection system was validated by Jones matrix theory and experiments, which shows the cosine relation between the output voltage of homodyne detection and the input voltage of phase modulator. The new scheme provides a new approach for continuous variable quantum key distribution.