The invention relates to a gantry single-arm mounting and inserting machine, comprising a main frame, a housing, XYZ axis motion devices, a mounting and inserting execution device, a PCB transfer device, a PCB positioning device, a feeding device, a detection deviation correction device, a control system and a human-computer interaction system. The feeding device is configured to convey the material to the designated positions on both sides of the main frame, XYZ axis motion devices drive the mounting and inserting execution device to absorb or grasp the material to reach the detection deviation correction device for deviation correction, the PCB in the mounting and inserting machine reaches the middle position of a general frame under the driving of the PCB transfer device, the PCB positioning device jacks up, limits and fixes the PCB, and the material after deviation correction is moved to the PCB for mounting and inserting. The devices cooperatively move under the control of the control system, the motion is smooth, the assembly position is accurate, the production speed is fast, the pass rate is increased, and mounting process and inserting process can be performed at the same time. The gantry single-arm mounting and inserting machine is strong in versatility, wide in application range, and capable of meeting diverse demands of customers.