The invention discloses a portable drilling machine, and relates to the technical field of machines and tools in the construction engineering industry. A key technology of no power and spring buffer control is adopted; an arched position of a rocker rod and a bushing are connected in a sleeving manner; a spring is inserted in a pipe at one end of the rocker rod, and is exposed outside the pipe to achieve effects of buffering and mastering the drilling depth in drilling; after the spring is inserted in the pipe at one end of the rocker rod, a drill bit is inserted in the spring for continuously inwards inserting, so that the drill bit is inserted into the bottom of the pipe of the rocker rod be penetrating through the spring; then, the drill bit and the rocker rod are fixed by a jackscrew; and the other end of the rocker rod and the inner circle of a bearing and the outer circle of the bearing and a handle are both fixedly connected in a tight fitting manner. The portable drilling machine is applied to the construction mounting engineering, and has the advantages of no need of external power supply and power, novel and unique concept, scientific and reasonable design, simple and skilful structure, quick assembly and disassembly, convenience for use and operation, stable and reliable effect and convenience for carrying and use.