The invention relates to the field of spot welding of batteries and particularly relates to a feeding mechanism of a spot welding device applied to battery cells. The feeding mechanism comprises a conveying device, a transferring device, a detection device and a blanking device, wherein the conveying device comprises a first conveying belt and a limiting shell; a groove body is arranged in the limiting shell; the first conveying belt is mounted in the groove body; a limiting block is arranged at one end close to the transferring device of the limiting shell; a first motor used for driving the first conveying belt is arranged at one end close to the transferring device of the first conveying belt. According to the feeding mechanism, the conveying device and the transferring device are used for putting the battery cells into the detection device, detecting the battery cells, changing directions of positive electrodes and negative electrodes of the battery cells and enabling the directions of the positive electrodes and the negative electrodes of all the battery cells; the second cylinder is used for conveying the battery cells to a guide rail; when the number of the detected battery cells reaches up to a certain number, a driving block is used for fastening the battery cells, moving to the upper part of a fixture along with a blanking rail and putting the battery cells into the fixture. The feeding mechanism is simple in structure; the feeding speed of the battery cells is improved, so that the overall production efficiency is improved.