The invention discloses an automatic feeding device of tin-soldering welding equipment and relates to the field of welding equipment. The automatic feeding device of the tin-soldering welding equipment comprises a fixing support; one end of the fixing support is provided with a square frame, and a motor base plate is installed in the square frame; a feeding guide pipe and a discharging guide pipe which are located in one straight line are installed on the front side of the motor base plate, a driving idler wheel and a driven idler wheel which are mutually attached are installed between the feeding guide pipe and the discharging guide pipe, a channel for tin wire penetration is formed between the feeding guide pipe, the gap between the driving idler wheel and the driven idler wheel and the discharging guide pipe; and a motor for driving the driving idler wheel to rotate is installed on the back face of the motor base plate. According to the automatic feeding device of the tin-soldering welding equipment, normal tin feeding actions can be conducted on the premise that a feeding photoelectric sensor and a discharging photoelectric sensor sense the tin wire at the same time; when the condition cannot be met at the same time, the motor receives a stop signal and is controlled to stop rotating, and an alarm is sent to remind, so that the situation of non-tin-wire welding is prevented, and welding efficiency is improved.