A pieces tensile testing machine is used to measure the tensile resistant value of pieces fixed on a brush head. The pieces tensile testing machine comprises a pulling device (1), a pieces chuck (2), a base plate (3), a frame (4) fixed on the base plate (3), a motor (5), a start button (51) of the motor (5), a brush head clamp (6) for positioning a brush head, a clamp slide board (7), and a moving mechanism (8). The brush head clamp (6) slides back and forth along the Y axis and is connected to the clamp slide board (7). The clamp slide board (7) slides left and right along the X axis and is connected to the base plate (3). The X axis and Y axis are perpendicular to each other. The motor (5) drives the pulling device (1) to go upwards or downwards through the moving mechanism (8). The pieces chuck (2) is hung under the pulling device (1) and over the brush head clamp (6). The provided pieces tensile testing machine can largely improve the accuracy of pieces tensile tests, and does not need artificial operation, and the tests are convenient and fast.