A vehicle window assembly with a self-adjusting molding, comprising a glass pane, an encapsulation fixed to an edge of the glass pane, a first insert mounted on the encapsulation, a molding mounted on the first insert, and an elastic portion, wherein: the first insert is movably connected to the encapsulation, the elastic portion is disposed at an abutting position of the first insert and a side wall of the encapsulation, the vehicle window assembly is configured to be mounted on a sheet metal, and when the vehicle window assembly is mounted on the sheet metal, the side wall of the encapsulation is configured to face the sheet metal, the elastic portion is configured to be pressed to generate a pre-tightening force, the first insert is configured to move towards the sheet metal under the action of the pre-tightening force, and the first insert is configured to drive the molding and make the molding be attached to the sheet metal; characterized in that: the encapsulation is provided with a second insert, and either: (a) the first insert is provided with a fitting portion in sliding fit with the second insert, the fitting portion being configured to make the first insert slide relative to the second insert, wherein, when the vehicle window assembly is mounted on the sheet metal, the first insert is configured to slide towards the sheet metal under the action of the pre-tightening force; or (b) the first insert is provided with a hinge portion hinged with the second insert, the first insert being rotatably connected with the second insert through the hinge portion, wherein, when the vehicle window assembly is mounted on the sheet metal, the first insert is configured to rotate towards the sheet metal under the action of the pre-tightening force. the first insert is movably connected to the encapsulation, the elastic portion is disposed at an abutting position of the first insert and a side wall of the encapsulation, the vehicle window assembly is configured to be mounted on a sheet metal, and when the vehicle window assembly is mounted on the sheet metal, the side wall of the encapsulation is configured to face the sheet metal, the elastic portion is configured to be pressed to generate a pre-tightening force, the first insert is configured to move towards the sheet metal under the action of the pre-tightening force, and the first insert is configured to drive the molding and make the molding be attached to the sheet metal; the encapsulation is provided with a second insert, and either: (a) the first insert is provided with a fitting portion in sliding fit with the second insert, the fitting portion being configured to make the first insert slide relative to the second insert, wherein, when the vehicle window assembly is mounted on the sheet metal, the first insert is configured to slide towards the sheet metal under the action of the pre-tightening force; or (b) the first insert is provided with a hinge portion hinged with the second insert, the first insert being rotatably connected with the second insert through the hinge portion, wherein, when the vehicle window assembly is mounted on the sheet metal, the first insert is configured to rotate towards the sheet metal under the action of the pre-tightening force. (a) the first insert is provided with a fitting portion in sliding fit with the second insert, the fitting portion being configured to make the first insert slide relative to the second insert, wherein, when the vehicle window assembly is mounted on the sheet metal, the first insert is configured to slide towards the sheet metal under the action of the pre-tightening force; or (b) the first insert is provided with a hinge portion hinged with the second insert, the first insert being rotatably connected with the second insert through the hinge portion, wherein, when the vehicle window assembly is mounted on the sheet metal, the first insert is configured to rotate towards the sheet metal under the action of the pre-tightening force.