The invention relates to a waste rubber continuous wave cracking device which comprises a bracket a microwave cracking mechanism installed on the bracket, and a feeding mechanism and a discharging mechanism which are connected with the microwave cracking mechanism, wherein the microwave cracking mechanism comprises a cracking chamber installed on the bracket and a microwave heating unit installed on the top of the cracking chamber; the cracking chamber comprises a cracking delivery mechanism installed inside the cracking chamber; the cracking delivery mechanism is used for loading and delivering the material from the feeding mechanism; the lower parts of both ends of the cracking chamber are respectively connected with the discharging mechanism; the cracking chamber and the horizontal direction form an inclination angle of 5-10 degrees; and the feed end of the cracking chamber is lower than the other end. The invention also relates to a method for performing continuous microwave cracking by using the device. The cracking device is compact and reliable, can implement continuity, and can enhance the quality and work efficiency of the cracked product.