Transportation method of bridge girder erection machine

The invention discloses a bridge girder erection machine transportation method which comprises the following steps: step 1, hoisting and splicing a main beam assembly, a front supporting leg assembly, a middle supporting leg assembly, a tail supporting leg assembly, a temporary supporting leg assembly, a longitudinal truss vehicle assembly and a crane carriage assembly of a bridge girder erection machine, so that a temporary supporting leg, a front supporting leg, a middle supporting leg and a tail supporting leg are sequentially mounted on a main beam; secondly, a front supporting leg, a middle supporting leg and a tail supporting leg are installed at the rear end of the main beam and supported in place, and a pair of fixed cross beams is installed; thirdly, the main beam is lifted, the temporary supporting legs are supported in place, the crane carriage is lifted, and the middle supporting legs are put away; fourthly, the main beam falls down, and the main transport vehicle and the auxiliary transport vehic