A grinding wheel machining device includes a movable platform and a grinding wheel machining mechanism. The grinding wheel machining mechanism includes a mounting assembly, a tool holder mounted on the movable member, a machining tool mounted on the tool holder, and an adjusting assembly. The mounting assembly includes a fixing base mounted on the movable platform, a movable member mounted onto the fixing base, and a rotation shaft received into the fixing base and the movable member. The machining tool includes a cutting edge. The adjusting assembly includes a reference member and an adjusting member. The reference member is fixed on the movable member and includes a reference surface. The reference surface is coplanar with a central axis of the rotation shaft. The adjusting member is received into the tool holder and threaded into the reference surface.