The invention provides a gear shifting reminding control device and method for reducing oil consumption, and the problem of fuel oil waste due to the fact that the gear selection is incorrect and thegear shifting is not timely caused is solved. The control method comprises the following steps of inputting an engine rotation speed sensor and a vehicle speed sensor acquisition signal to an MCU, theMCU is used for outputting a level signal and a display signal according to an internal algorithm and then outputting a level signal and a display signal for prompting the gear shifting, the gear sensor inputs the gear signal to the MCU, and the MCU adjusts the working condition of the engine in time according to the gear signal and the vehicle speed signal. According to the acquired vehicle speed and the engine rotating speed signal, the pre-shifting position can be calculated through an internal algorithm of the MCU, a driver can be reminded to shift in time, the MCU controls the working conditions of the engine in time according to the gear information, and fuel is saved.