An electric reciprocating saw comprises a base frame, a power driving mechanism and a saw blade, wherein the power driving mechanism is arranged on the base frame, and the saw blade is driven by the power driving mechanism. A stopper is arranged in the front of the base frame, the saw blade linearly extends forwards from the stopper, a positioning clamp is arranged on the base frame, the positioning clamp is connected with the base frame by rotating around a first rotating shaft, the positioning clamp comprises a positioning clamp body, one side edge, used for abutting against wood to be cut, of the positioning clamp body is in an arc concaved inwardly, and the arc edge is provided with a plurality of teeth used for abutting against the wood to be cut. When the positioning clamp is in use, a clamping space capable of containing the wood to be cut can be formed between the positioning clamp body and the stopper; when cut by the electric reciprocating saw, the wood can be clamped between the stopper and the positioning clamp body, and friction is generated between the teeth on the positioning clamp and the wood, so that the wood is stably clamped between the stopper and the positioning clamp body, cutting is convenient to finish, and the structure is simple.