The invention relates to a steel die forging piston heat treatment adjustable temperature furnace with energy saving and emission reduction effects and a heat treatment process method thereof. Compared with the prior art, the defects that in the steel die forging heat treatment process, heat energy is wasted, the temperature control difficulty is large, and the internal quality of a produced steeldie forging piston is unstable are overcome. An inlet of a heat return pipeline is formed above a rapid cooling device; an outlet of the heat return pipeline is installed above a cooling section of the heat treatment device, a cold air inlet is formed in the side portion of the rapid cooling device and located below the conveying belt, the cold air fan is installed beside the rapid cooling device, an air inlet of the cold air fan faces the outside, and an air outlet is connected with the cold air inlet of the rapid cooling device through a pipeline. Based on the novel heat treatment process method, the requirements of customers for the metallographic structure and the grain size in the steel die forging piston are met, the percent of pass is increased, and meanwhile the effects of energyconservation and emission reduction are achieved.