Based on 3D particle-in-cell (PIC) numerical simulation method, the high quality, high energy proton beam is transmitted and focused on the far end via a pulse current solenoid. Simulation results show that proton beam with peak energy of 250 MeV, energy spread of 10% and a spatial divergence angle less than 15 mrad can be focused on a spot 2.5 m away from the proton source, after transported in a 760-mm pulse power solenoid under magnetic field strength of 10.87 T. The focal spot cross section diameter is 1.2 mm, less than the initial proton beam spot size; meanwhile, the number loss of proton beam is less than 3%. We conclude that it is feasible to use a powered solenoid to transmit and regulate a high energy proton beam. This scheme can be used to optimize the proton beam quality and promote the laser-driven proton acceleration to be applied early in the fields such as cancer treatment, where high proton beam unipotency and small divergence angle are required.