The invention discloses a apparatus and a method for rapid measurement of heat capacity of a thin film material. Specifically, the apparatus comprises a control device, a clock synchronizer, a flat peak laser device, a rapid thermometer and a heat capacity output device; the control device and the clock synchronizer are signally connected, and the clock synchronizer is signally connected to the flat peak laser device and the rapid thermometer; In the working state, the control device sends a start signal to the clock synchronizer, and the flat peak laser device and the fast thermometer coordinately cooperate; the flat peak laser device irradiates a laser with a spatially flat peak to the surface of the sample; At the same time, the rapid thermometer captures the surface temperature of the sample at a certain point in time during the heating process of the sample, and inputs the measured data into the heat capacity output device to obtain the desired heat capacity parameter. The device of the invention has simple structure, high efficiency and accuracy, and can provide reliable parameter data for the current thermal property setting of various ultra-thin semiconductor films.