Preparation method of fireproof anti-cracking ultra-high performance concrete beam

The invention belongs to the technical field of constructional engineering application, and particularly relates to a preparation method of a fireproof anti-cracking ultra-high performance concrete beam. Comprising a concrete beam body and a steel bar net rack arranged on the concrete beam body, and the steel bar net rack comprises steel bar net rings arranged in the long edge direction of the concrete beam body at intervals, and transverse steel bars and longitudinal steel bars arranged in the steel bar net rings; the concrete beam body comprises a mixed cement part and an ultra-high-performance concrete part wrapping the mixed cement part, the structure of an existing ultra-high-performance concrete beam is improved, the ultra-high-performance concrete wrapping the steel bar net rack is doped with the foaming cement, the closed-cell characteristic of the foaming cement is utilized, and the foaming cement is added into the ultra-high-performance concrete; and the whole heat conduction system is lowered, so t