In order to satisfy the demand of ground tests of ramjet, a kerosene heater based on gas heating was designed, and tests were taken to do research on the influence of several factors on the operation performance. The results indicate that the kerosene heater has a strong ability of heating, less responding time, and it can produce supercritical/cracked kerosene online; the main factors that influence operation performance of kerosene heater are temperature, mass flow rate of gas, and mass flow rate of kerosene. The kerosene heater can accommodate temperature of kerosene in a large range through control of temperature and mass flow rate of gas. Then it can satisfy demand of different status of ramjet ground tests.