An apparatus and test method for simulating spark discharge of a high-voltage electrostatic precipitator are provided. The simulation apparatus includes a pulse power supply configured to provide a test voltage, an anode cylinder configured to simulate an anode of a precipitator, a cathode rod configured to simulate a cathode of the precipitator, a pulse capacitor unit configured to simulate an electrode capacitor of the precipitator, an insulating support configured to hang the cathode rod, a voltage divider configured to measure an electrode voltage, and a grounded current sampling unit configured to measure grounded current. The simulation apparatus simulates a discharge process of the high-voltage electrostatic precipitator to measure discharge characteristic parameters such as discharge current and discharge energy of the high-voltage electrostatic precipitator. In this way, characteristics of spark discharge of the precipitator under different load conditions are simulated.