The invention discloses an all-solid-state battery and a preparation method. The preparation method of the all-solid-state battery comprises the steps of: step S1, coating the anode slurry containingpolycarbonate alkenyl ester on an anode current collector; step S2, overlaying and drying the solid electrolyte membrane containing the polycarbonate alkenyl ester on the anode current collector coated with the anode slurry; step S3, performing the magnetron sputtering on the dried solid electrolyte membrane to form a silicon layer; and step S4, performing the magnetron sputtering on the surface of the silicon layer to form a nickel layer or a copper layer. The all-solid-state battery prepared by the preparation method runs normally without an extra pressurizer; and compared with the all-solid-state battery that requires the extra pressurizer, the energy density is improved.