The utility model relates to a multifunctional tunnel working rack comprising a walking device, a lower skeleton part, an upper skeleton part and a lifting system; the lower skeleton part comprises 8 supporting columns with box-shaped structures, box-shaped cross beams, box-shaped longitudinal beams, horizontal operating platforms on the two sides and a top working platform; the horizontal operating platforms on the two sides comprise cross beams of the horizontal operating platforms, steel pipes and inclined support beams; and top cross beams and longitudinal beams are arranged on the top working platform. The multifunctional tunnel working rack provided by the utility model has the beneficial effect that the rack safely moves up and down, the horizontal expansion arm is free to construct and move and quick to withdraw and move front and back and, no steel pipe frame platform is necessary to be erected or detached, and the horizontal and quick construction demand can be satisfied. The multifunctional tunnel working rack has a simple structure, easiness in operation, stable and safe integral stress, high processing and reformation speed and good economic benefit.