The invention discloses a method for determining content of coal pyrolysis resultant. The method comprises (1) obtaining the mass of C, H, O, N and S in 100 g dry ash-free basis coal by employing an element analysis process and respectively recording as mC, mH, mO, mN and mS g, and employing a coal industrial analysis process to measure the caloric value Q[net ,dnf] of combustible substances in dry ash-free basis coal and measure the mass of coke and volatile compounds generated after pyrolysis respectively to be mFC and mV g; (2) calculating the air quantity demanded by combustion of 100 g dry ash-free basis coal to be mA g according to a combustion chemical formula; (3) obtaining the value of a, b and c from a coal pyrolysis formula (1) according to the data in the step (1) by balancing the mole numbers of N and S elements, thereby respectively determining the substance amount of C, N and S elements in coal, and calculating x[i] values according to a formula (14) by employing a process of solving a minimum value of a function, thereby determining the content of H2O, CO, CO2, a hydrocarbon mixture and H2.