The invention discloses a gasifier provided with a heat recovery system. The gasifier comprises an outer shell, an inner shell, a spray nozzle and a gas slag channel, wherein the inner shell is arranged in the outer shell, separated from the outer shell and divided into an upper inner shell and a lower inner shell, a gasifying chamber is defined in the upper inner shell, a heat recovery chamber and a quenching chamber are defined in the lower inner shell, a first cooling water inlet and a first cooling water outlet are formed in the upper inner shell, and the lower inner shell is provided with independent second cooling water inlet and second cooling water outlet; the spray nozzle is arranged at the tops of the outer shell and the upper inner shell, penetrates inlets of the outer shell and the upper inner shell and extends into the gasifying chamber; the gas slag channel is formed between a bottom outlet of the upper inner shell and a top inlet of the lower inner shell. According to the gasifier provided with the heat recovery system, heat recycling can be realized, energy can be saved, and the rate of multipurpose utilization of energy can be increased.