In this paper,we demonstrate an FPGA b a sed gated mode single photon detector for the InGaAs/InP infrared avalanche phot on diode.Thank s to the FPGA′s flexibility,the detector′s gate repeating frequency can reach up to 100MHz,gate width down to 1ns,and holdoff time is set at 109ns,all of which contribute to low afterpulsing probability.Moreover,all these parameters are flexible to adjust via a computer interface.The performance of this single photon detector is characterized by the platform,working at temperature of 218K .And it yields only 2×10－5/ns dark count rate (DCR) when photon detection efficiency is 10%,and the maximum photon detection efficiency o f 14% is obtained.It is measured that its effective gate width is 0.79ns,and when the holdoff time between gates exceeds 109ns,the afte rpulsing probability can drop to a negligible level. Performance at different temperatures is also investigated.This near-infrared s ingle photon detector can realize high photon detection efficiency,low dark count rate and low afterpulsing probability while working a t 100MHz of gate repeating frequency,which is size-efficient,cost-effective a nd easy to adjust.