Provided is a high-frequency spark testing machine which is simple in structure, convenient to disassemble and assemble, and convenient to maintain. The high-frequency spark testing machine includes a carriage, a leakage transformer, a discharge ball rack, a capacitive voltage divider and a Tesla air-core transformer, wherein the leakage transformer, the discharge ball rack and the Tesla air-core transformer are sequentially connected in parallel in the carriage; the capacitive voltage divider is connected in series between the discharge ball rack and the Tesla air-core transformer. The high-frequency spark testing machine can be used for quickly detecting faulty insulators on an assembly line. Because a gap G in the discharge ball rack adopts tungsten material as a discharge electrode material, electrode carbonization does not appear even if frequent discharge flow is performed in a high-temperature environment for a long time, and the service lift of the discharge electrode is effectively prolonged. Advantages are as follows: 1) since the high-frequency spark testing machine is provided with an enclosed air gap, a plate electrode made of tungsten material and an air blowing and filtering system, the purity of air in the gap and good insulating property in a severe assembly line environment are guaranteed; and 2) the high-frequency spark testing machine can perform high-frequency spark screening tests on two insulators at once, and therefore helps to improve the assembly line testing speed.