The invention discloses an oil heater. The oil heater comprise two oil pipes which are distributed at intervals in top and bottom directions, and a plurality of heat dissipating sheets of which two ends are correspondingly arranged on the two oil pipes, wherein an oil channel which communicates with the two oil pipes is arranged in each heat dissipating sheet; an air chamber which is arranged at interval relative to the corresponding oil channel is arranged on the edge of at least one side of each heat dissipating sheet; the air chamber is provided with an air inlet and a top air outlet, and the top air outlet is formed in the top part of the air chamber; the air chambers in the same side of every two adjacent heat dissipating sheets are in contact. With the adoption of the oil heater, the heat dissipating area of the side edges of the heat dissipating sheets can be increased, so that the flowing intensity of air on the inner surfaces of the heat dissipating sheets can be improved, and as a result, the temperature of the side edges of the heat dissipating sheets can be reduced, the heat dissipating capacity of the heat dissipating sheets can be improved, and a user can be prevented from being scalded while using the oil heater.