The invention discloses a semi-solid friction brazing method for dissimilar metals based on high-frequency assistance, which includes the following steps: step 1, preparing a stud to be welded and a workpiece to be welded, and the welding end of the stud to be welded is processed into a tapered step shape, taper thread shape or taper step thread shape, the workpiece to be welded is processed with a preset hole, and the solder is placed on the inner wall of the preset hole of the workpiece to be welded. Step 2, using a high frequency induction coil to Heating the welding end of the welding stud to 300-500°C and keeping it warm for 1-5 minutes; step 3, the friction stage, rubbing at a speed of 600-1500r / min and a friction pressure of 10-40MPa for 3-8s; step 4, the upsetting stage, friction rotation Emergency stop, the emergency stop time is less than 0.5s, the upsetting pressure is 15-60MPa, the upsetting time is 3-10s, and the displacement of the stud to be welded during the upsetting stage is 1-3mm. Step 5: After upsetting, hold the load under a pressure of 15-60 MPa for 10-25 seconds, and then air-cool to room temperature. It can realize the high-quality connection of dissimilar metals, has the dual advantages of "metallurgical bonding + mechanical occlusion", and improves the mechanical properties and welding efficiency of the joint.