The utility model discloses a saw blade clamping mechanism of a reciprocating saw. The saw blade clamping mechanism of the reciprocating saw comprises a rear clamping ripping fence mechanism, a front clamping ripping fence mechanism and a blade back. The front clamping ripping fence mechanism comprises a third clamping elastic piece, a fourth clamping elastic piece, a first screw, a second screw, a nut, an elastic part and a U-shaped adjustment bolt, wherein the first screw and the second screw are arranged on the fourth clamping elastic piece, penetrates through a second guide groove of the blade back and is connected with the third clamping elastic piece, a first part of the U-shaped adjustment bolt is connected with the fourth clamping elastic piece, penetrates through the second guide groove of the blade back and is connected with the third clamping piece, the nut is arranged at the end of the first part, the elastic part is arranged between the nut and the third clamping elastic piece, and a second part of the U-shaped adjustment bolt is connected with the fourth clamping elastic piece, penetrates through a first guide groove and is connected with the third clamping elastic piece. The saw blade clamping mechanism of the reciprocating saw can meet the cutting requirements of objects with different widths and bring great convenience to a user.