A power converter based on a high voltage thyristor, comprising an air cooling radiator (100), a thyristor phase module (V1), and a diode phase module (V2). The thyristor phase module (V1) comprises a first thyristor (S1) and a second thyristor (S2) connected to each other. The diode phase module (V2) comprises a first diode (D1) and a second diode (D2) connected to each other. The connection point between the anode of the first thyristor (S1) and the cathode of the second thyristor (S2) is a first input end (AC-1) of an alternating current power supply, and the connection point between the anode of the first diode (D1) and the cathode of the second diode (D2) is a second input end (AC-2) of the alternating current power supply. The cathode of the first thyristor (S1) and the cathode of the first diode (D1) are also first direct current output ends (DC+), and the anode of the second thyristor (S2) and the anode of the second diode (D2) are also second direct output ends (DC-). The thyristor phase module (V1) and the diode phase module (V2) are both on the upper surface of the air cooling radiator (100). The problems in a power converter of a complicated assembly structure and large volume of the whole apparatus, as well as inconvenience in replacement and maintenance are solved.