In view of the scenarios where the resources of cloud terminal users are limited， the traditional attribute based encryption schemes have the disadvantages of high computing cost and being unable to achieve real-time revocation. In order to realize the safe and efficient sharing of cloud data， an attribute based encryption scheme based on Elliptic Curve Cryptography （ECC） algorithm and supporting fine-grained revocation was proposed. In the scheme， the relatively lightweight scalar multiplication on the elliptic curve was used to replace the bilinear pairing with higher computational cost in the traditional attribute based encryption schemes， thereby reducing the computational cost of users during decryption in the system， improving the efficiency of the system and making the scheme more suitable for resource constrained cloud terminal user scenarios. In order to reduce the redundant attributes embedded in the ciphertext to shorten the length of the ciphertext， the more expressive and computationally efficient Ordered Binary Decision Diagram （OBDD） structure was used to describe the user-defined access policy. An attribute group composed of users with the attribute was established for each attribute， and a unique user attribute group key was generated for each member of the group. When the attribute revocation occurred， the minimum subset cover technology was used to generate a new attribute group for the remaining members in the group to realize real-time fine-grained attribute revocation. Security analysis shows that the proposed scheme has the indistinguishability of selective plaintext attacks， forward security and backward security. Performance analysis shows that the proposed scheme outperforms （t，n） threshold secret sharing scheme and Linear Secret Sharing Scheme （LSSS） in terms of access structure expression and computing capability， and has the decryption computational efficiency meeting the need of resource constrained cloud terminal users.