The invention relates to a portable climbing device. The portable climbing device comprises a rope ladder, wherein one end of the rope ladder is fixed on a contraction and release part of the rope ladder and can be wound for contraction and release on the contraction and release part of the rope ladder. The portable climbing device further comprises a braking part which can brake the contraction and release part of the rope ladder. The portable climbing device is simple and reasonable in structural design, light in weight, small in size and convenient to climb and carry, and successfully solves the technical problem of low mounting process quality of transmission line suspension composite insulator strings. The technology of the portable climbing device has the advantages of effectively protecting composite insulator strings, being convenient to operate and mount, quick and convenient, low in construction security risk, high in universality, attractive in appearance, remarkable in effect, high technical reliability and long service life, saving money and the like, and fills the technical blank of mounting and manufacture processes of upper and lower wires during construction of suspension hardware fitting composite insulator strings of transmission towers in China.