The invention discloses a cloud storage data sharing method for forward security key aggregation. The method comprises the steps that firstly, when a data owner uploads files, identifying each file is, and then generating and sending a public parameter set and to a cloud storage platform; calling a key generation algorithm to generate a public and private key pair required by encryption, and encrypting the original file by calling a public key to obtain a ciphertext set; enabling a data owner to request a data requester; generating an aggregation key by combining a main key, identity information of a requester and a timestamp based on a generation element and sending the key to a data requester through a secure channel, enabling the data requester to download an encrypted file and decrypts a ciphertext by utilizing the aggregation key, and the requested file can be successfully obtained after the identity information and the key valid time are verified. According to the invention, the security and privacy of user data recording can be effectively ensured while the compactness of the secret key is ensured.