A packaging method for organic semiconductor device, comprising steps of: manufacturing an organic semiconductor device on a flexible base ; forming a photoresist block having a predetermined interval with respect to the organic semiconductor device and located at two sides of the organic semiconductor device on the flexible base ; depositing an inorganic layer on the photoresist block , the organic semiconductor device and the flexible base ; removing the photoresist block and the inorganic layer on the photoresist block ; and depositing an organic layer on the inorganic layer disposed on the organic semiconductor device , the step of forming the photoresist block comprises steps of: coating a photoresist layer on the organic semiconductor device and the flexible base ; using a predetermined mask plate to perform an exposure to the photoresist layer , wherein the mask plate includes a light-shielding portion and a light-transmitting portion respectively located at two sides of the light-shielding portion , the light-shielding portion is disposed above the organic semiconductor device , two sides of the light-shielding portion respectively extend beyond two sides of the organic semiconductor device , and a projection of the organic semiconductor device on the light-shielding portion is fully inside the light-shielding portion ; and developing the photoresist layer after being exposed in order to remove the photoresist layer corresponding to the light-shielding portion so as to form the photoresist block . manufacturing an organic semiconductor device on a flexible base ; forming a photoresist block having a predetermined interval with respect to the organic semiconductor device and located at two sides of the organic semiconductor device on the flexible base ; depositing an inorganic layer on the photoresist block , the organic semiconductor device and the flexible base ; removing the photoresist block and the inorganic layer on the photoresist block ; and depositing an organic layer on the inorganic layer disposed on the organic semiconductor device , the step of forming the photoresist block comprises steps of: coating a photoresist layer on the organic semiconductor device and the flexible base ; using a predetermined mask plate to perform an exposure to the photoresist layer , wherein the mask plate includes a light-shielding portion and a light-transmitting portion respectively located at two sides of the light-shielding portion , the light-shielding portion is disposed above the organic semiconductor device , two sides of the light-shielding portion respectively extend beyond two sides of the organic semiconductor device , and a projection of the organic semiconductor device on the light-shielding portion is fully inside the light-shielding portion ; and developing the photoresist layer after being exposed in order to remove the photoresist layer corresponding to the light-shielding portion so as to form the photoresist block . coating a photoresist layer on the organic semiconductor device and the flexible base ; using a predetermined mask plate to perform an exposure to the photoresist layer , wherein the mask plate includes a light-shielding portion and a light-transmitting portion respectively located at two sides of the light-shielding portion , the light-shielding portion is disposed above the organic semiconductor device , two sides of the light-shielding portion respectively extend beyond two sides of the organic semiconductor device , and a projection of the organic semiconductor device on the light-shielding portion is fully inside the light-shielding portion ; and developing the photoresist layer after being exposed in order to remove the photoresist layer corresponding to the light-shielding portion so as to form the photoresist block . <EOS>