The invention discloses a tin device for processing printed circuit boards. The structure of the tin device comprises a base, a sliding workbench, stand columns, a tin supply system, a slider, a sliderail, a tin spraying head and a clamp, the sliding workbench is mounted on the base, a clamp is arranged on the sliding workbench, the two sides of the base are respectively connected with the standcolumns, the top of the stand columns are connected with the slide rail, the slide rail is in sliding connection with the slider, the slider is connected with the tin spraying head, the tin spraying head is connected with the tin supply system, the tin supply system is arranged on the side surface of the stand column, the clamp comprises a protective base, a moving device, a first clamping plate and a second clamping plate, a moving device is arranged in the protective base, the first clamping plate and the second clamping plate are parallel to each other and are arranged on the protective base, the moving device is connected with the first clamping plate and the second clamping plate respectively. The tin device has the benefit effect that the double-panel type printed circuit board is clamped and fixed through the hourglass-shaped pulley, the circuit board can be kept in a horizontal state, soldering is facilitated better, and tilting is prevented.