A molding method, comprising: providing a molding device, wherein the molding device includes a first mold, a second mold corresponding to the first mold, a mold cavity defined by the first mold and the second mold and having a volume when the first mold is engaged with the second mold and the molding device is at a closed configuration, a feeding port in communication with the mold cavity, and a junction point in connection with the mold cavity; engaging an outlet of an injector to the feeding port, wherein the injector may be disposed over the molding device, wherein the injector includes an outlet; injecting a molding material including a blowing agent into the mold cavity from the feeding port by the injector; the method characterized in that: applying a clamping force to the molding device to maintain the first mold engaging with the second mold and the molding device at the closed configuration; andafter the injection of the molding material into the mold cavity, injecting a gas into the mold cavity through the junction point to increase a pressure inside the mold cavity to a predetermined pressure for maintaining the blowing agent in a supercritical state, wherein the clamping force is continuously applied to the molding device during the injection of the molding material and the injection of the gas to maintain the molding device at the closed configuration and the mold cavity in the volume. providing a molding device, wherein the molding device includes a first mold, a second mold corresponding to the first mold, a mold cavity defined by the first mold and the second mold and having a volume when the first mold is engaged with the second mold and the molding device is at a closed configuration, a feeding port in communication with the mold cavity, and a junction point in connection with the mold cavity; engaging an outlet of an injector to the feeding port, wherein the injector may be disposed over the molding device, wherein the injector includes an outlet; injecting a molding material including a blowing agent into the mold cavity from the feeding port by the injector; the method characterized in that: applying a clamping force to the molding device to maintain the first mold engaging with the second mold and the molding device at the closed configuration; andafter the injection of the molding material into the mold cavity, injecting a gas into the mold cavity through the junction point to increase a pressure inside the mold cavity to a predetermined pressure for maintaining the blowing agent in a supercritical state, wherein the clamping force is continuously applied to the molding device during the injection of the molding material and the injection of the gas to maintain the molding device at the closed configuration and the mold cavity in the volume. applying a clamping force to the molding device to maintain the first mold engaging with the second mold and the molding device at the closed configuration; andafter the injection of the molding material into the mold cavity, injecting a gas into the mold cavity through the junction point to increase a pressure inside the mold cavity to a predetermined pressure for maintaining the blowing agent in a supercritical state, wherein the clamping force is continuously applied to the molding device during the injection of the molding material and the injection of the gas to maintain the molding device at the closed configuration and the mold cavity in the volume.