The tunneling breakdown electric field, avalanche breakdown electric field, multiplication region width depend on exceed breakdown voltage of InGaAs/InP SPAD was researched as a key point. The calculated method of exceed breakdown voltage was presented. The basic performance of single photon avalanche diode(SPAD) depends on their excess bias, multiplication region width, working temperature, electric-field distribution and quantum efficiency has been analyzed. According to these analysis, a designed solution of InGaAs/InP SPAD has been presented, and then the device was manufactured later. Under the conditions of -40 ℃ and exceed breakdown voltage over 2 V, the InGaAs/InP SPAD of Φ200 μm diameter exhibits dark count rates(DCR) below 20 kHz and photon detection efficiency(PDE) of 20%(1 500 nm). Under the conditions of -40 ℃ and exceed breakdown voltage over 2.5 V, the InGaAs/InP SPAD of Φ50 μm diameter exhibits dark count rates(DCR)below 2 kHz and photon detection efficiency(PDE) of23%(1 550 nm). Finally, the experimental results were analyzed.