The multiplying ability is the greatest advantage of fiber Bragg grating (FBG) sensor, which is easy to realize the large-scale remote measurement system. But at present, the measuring accuracy of optical fiber sensing network constituted by WDM drops obviously when the measuring point quantity increases, and the structure that connected the light source and FBG sensors in series on the same optical fiber reduces the signal-to-noise ratio (SNR) and reliability, and makes the system difficult to expand. In order to solve these problems, a new kind of sensing network called two-fiber sensing network is proposed. The two-fiber sensing network connecte the light source and FBG sensors in parallel between two independent fibers, which increases the SNR, decreases the system fault rate and makes the system easy to expand. At the same time, sensors with same central wave length but different spectrum can be differentiated through the autocorrelation operation of photodiode output signal, which guaranteed the measuring accuracy is not influenced by the measuring point quantity of system. The theoretical analysis and experiment study indicate that the two-fiber sensing network has a fixed SNR and a lower fault rate, and the system’s measuring accuracy is not influenced by its scale, therefore it is a kind of optical fiber sensing network which suits for engineering application.