Abstract: In order to improve the performance of single photon detectors, a low cost, ultra-wideband, low noise preamplifier design and fabrication are developed utilizing high electron mobility transistors based on hybrid integrated negative feedback structure. Then the optimization and simulation of the preamplifier are finished using ADS. Power gain of the preamplifier is 19. 5dB±0. 61dB in the working band from 5MHz to 6GHz, noise coefficient is less than 2. 6dB, and input/ output voltage standing wave ratio is less than 1. 8. The results of simulation and experiment show that the preamplifier has a ten-time amplification of amplitude for the sub-nanosecond level signal derived from avalanche photoelectric diode. So, the preamplifier can meet the increasing detection frequency demand of single photon detector.