The invention relates to a method for measuring the radius-thickness ratio of flaky metal powder. The method comprises the following steps: step 1, manufacturing a supporting body with an end plane by using inlaid powder; step 2, coating the end plane of the supporting body with turbid liquid containing the flaky metal powder, wherein the metal powder is dispersed in a liquid dispersing agent so as to form the turbid liquid; step 3, adding the inlaid powder into the end plane after the dispersing agent is volatilized; step 4, allowing the supporting body and the inlaid powder to form a whole; step 5, splitting the whole so as to form a splitting surface which penetrates through the end plane in a direction perpendicular to the end plane; and step 6, measuring the length-width ratio of cross sections of multiple pieces of flaky metal powder on the splitting surface, thereby obtaining the radius-thickness ratio of the flaky metal powder. According to the method disclosed by the invention, the radius-thickness ratio of the flaky metal powder can be conveniently measured, and the precision of the obtained radius-thickness ratio is high.