The invention discloses a composite solid-state polymer electrolyte and an all-solid-state lithium battery. The composite solid-state polymer electrolyte comprises organic micro-nano porous granules, a polymer having lithium ion conducting capability and a lithium salt; the composite solid-state polymer electrolyte takes the organic micro-nano porous granules as filler; and natural compatibility exists between the organic filler and the polymer matrix. The composite solid-state polymer electrolyte disclosed by the invention has high electrochemical window (4.2-5V), excellent interface stability with a lithium-based negative electrode material, and low interface impedance. The all-solid-state lithium battery, assembled by the composite solid-state polymer electrolyte disclosed by the invention, is high in cycling performance and rate capability.