Portable combined assembled excavation support bench suitable for multiple benching tunnelling methods

The invention discloses a portable combined assembled excavation support bench suitable for multiple benching tunnelling methods. The excavation support bench comprises an upper bench and a lower bench; the upper bench is of a step shape and comprises a first step and a second step which are connected up and down, and the transverse dimension of the lower bench is larger than the transverse dimension of the upper bench; and the first step, the second step and the lower bench comprise a plurality of vertical door frames and a plurality of horizontal brackets correspondingly, the first step is provided with a first work platform in an erecting mode, the second step is provided with a second work platform in the erecting mode, and the lower bench is provided with a third work platform in theerecting mode. The portable combined assembled excavation support bench suitable for the multiple benching tunnelling methods is suitable for all working procedures of excavation and support in two-step and three-step constru