Abstract: The photovoltaic resources are abundant in the high altitude area of northwest China, but the network frame is weak in this kind of area, and it is urgent to carry out the detection of Photovoltaic grid connected network test. It is necessary to solve the problem of system insulation safety with Low Voltage Ride-Through (LVRT) test for photovoltaic power generation system at high altitude area. In this paper, the principle of LVRT experimental system of photovoltaic power generation is analyzed. The factors affecting transient overvoltage of the system are analyzed also. According to a 35 kV LVRT experiment, the simulation calculation is studied by using ATP, sums up the test point 0.1μF grid connected capacitance and resistance of 100Ω can effectively reduce the peak of the transient overvoltage, determine the effective measures of overvoltage suppression test process.