Waste liquid incinerator with built-in evaporation device

The invention relates to a waste liquid incinerator with a built-in evaporation device, which comprises an incinerator body and an incineration chamber and the evaporation device which are arranged in the incinerator body. A waste gas inlet of the incineration chamber is communicated with an outlet of a waste liquid flow passage of the evaporation device by a waste liquid spray gun and a pipeline; a flue gas outlet of the incineration chamber is communicated with an inlet of a flue gas flow passage of the evaporation device; high-temperature flue gas flowing out of the incineration chamber and waste liquid to be incinerated implement heat exchange by the evaporation device, so that the waste liquid is evaporated into gas before incineration, thereby improving incineration efficiency.