An IMR-transfer (in mold release) method includes the following steps: a foil is sent between a first mould and a second mould, wherein the first mould is provided with a mould cavity and the second mould includes an air vent with a pressure release valve and an air inlet; the foil is pressed onto the first mould so as to form an airtight space between the foil and the first mould; the airtight space is vacuumized for adsorbing the foil into the mould cavity of the first mould; the first mould and the second mould are matched; and a medium is utilized to press the foil so that the foil is fully jointed to the mould cavity of the first mould; glue is injected into the mould cavity; and the moulds are opened after cooling. The method can greatly extend the stretched length of the foil between the first mould and the second mould via the dual action of the air blowing pressure of the first mould and the air evacuation of the second mould, and the prefect joint effect of the foil and the mould cavity of the second mould can be achieved even in the condition of small angle.