The internal transition holes in complex hydraulic chamber affect the performance, reliability and service life of hydraulic system. Conventional deburring methods can not remove burr effectively at present. In thermal energy method, combustible gas is used as medium and the burr can be melted and oxidized through immediate deflagration of highpressure combustible gas. After studying the principle and features of thermal energy method, deburring experiment was carried out by setting different parameters.The result shows that the thermal energy method can be used to remove burr effectively.