The invention discloses a dangerous solid waste transportation and treatment device, which comprises a main body, an outer dovetail seat, an outer push rod motor, an inner dovetail seat, an inner push rod motor, an outer sliding frame, an inner sliding frame, an unfolding part and an adjusting part. In the reverse moving process of the outer sliding frame and the inner sliding frame, all supporting cylinders and supporting rods can make reverse contact and slide, then a conveying belt can be continuously supported, and therefore conveying safety and stability can be guaranteed, and in the reverse moving process of the outer sliding frame and the inner sliding frame, a scraper blade can scrape away granular waste remaining on the conveying belt, a cleaning roller can further clean the upper end face of the conveying belt, and therefore it can be guaranteed that the conveying belt is sufficiently clean during rolling, damage to the conveying belt can be prevented, the position of a fork cylinder can be reversely adjusted after a transmission motor is powered on, therefore, stability and safety of transportation are indirectly guaranteed.