The invention discloses full-solid-state multi-arm star-shaped block polymer based electrolyte. The preparation of the multi-arm star-shaped block polymer based electrolyte has the technical characteristics that a multi-arm star-shaped block polymer is synthesized by a core-first and arm-second method; a core of the multi-arm star-shaped block polymer is a hyperbranched polymer; each arm of the multi-arm star-shaped block polymer is composed of a rigid chain segment and a polymethoxyl polyethylene glycol acrylate chain segment; the rigid chain segment provides the mechanical strength and a polyethylene oxide (PEO) side chain can be used for dissolving salt and can be used as an ionic conduction base body. The polymer electrolyte does not contain any combustible and volatile solvent and a film can be formed by a solution pouring method; the room-temperature conductivity is close to 10<-4>s/cm. The polymer electrolyte has potential applications on electrochemical devices including lithium ion secondary batteries, ultra-capacitors, electronic sensors, electrochromism devices and the like.