A local cooling oil bath heating method, the local cooling oil bath heating method comprises the following steps of: vacuuming the closed oil bath, filtering the oil in the normal-temperature oil storage tank, injecting into the three chambers of the closed oil bath, starting the heating of the electric heating tube, and stopping heating after the temperature of the three chambers is greater thanor equal to 200 DEG C; when the oil bath needs to be cooled, opening the electromagnetic cut-off valve at the oil outlet end of the middle chamber to flow into the high-temperature storage tank, closing the electromagnetic cut-off valve, and then opening the electromagnetic cut-off valve of the oil inlet end of the middle chamber; the oil pump is started again to inject the oil of the normal temperature storage tank into the chamber of the oil bath, and the electric heating tube is heated again; at the same time, the hot oil in the high-temperature storage tank is cooled by the S-type coolingcoil of the water-cooling tank and flows into the normal-temperature storage tank; repeating the steps of ''heating-exhausting hot oil from the middle cavity-injecting cold oil into the middle cavity-cooling backflow of hot oil'' to achieve local rapid cooling and overall rapid heating of the oil bath. According to the local cooling oil bath heating method, the method can not only rapidly heat butalso rapidly cool, and is particularly suitable for the automatic energy storage high-pressure liquid injection CO2 phase change pulse coal rock body fracturing device.