The invention discloses a mechanical gasoline storage tank. The mechanical gasoline storage tank comprises a hollow shell and a support base fixed to the bottom of the hollow shell, wherein a gasoline storage space is formed in the hollow shell; a liquid inlet pipeline communicating with the gasoline storage space is fixed to the centre of one end surface of the hollow shell; a liquid drainage pipeline communicating with the gasoline storage space is fixed to the bottom of the hollow shell; an exhaust pipeline communicating with the gasoline storage space is fixed to the top of the hollow shell; and a first check valve is installed in an intake pipeline. According to the mechanical gasoline storage tank disclosed by the invention, gasoline and gases generated due to the volatilization of gasoline are separately stored, so that the effective storage capacity of the gasoline storage space is improved; and in addition, the destructibility of a gas pressure to components at a gasoline storage part is lowered, and the device is capable of compressing the generated gases, thereby improving the storage capacity of a gas storage space.