Ciphertext-policy attribute-based encryption (CP-ABE) is a kind of asymmetric encryption which is widely used in cyber-physical system and Internet of Things. In CP-ABE, access structure is an important component affecting the efficiency and performance greatly in several stages, such as encryption stage, key generation stage, decryption stage. However, the existing CP-ABE schemes have low efficiency because of the application of traditional access structures. In order to alleviate the aforementioned problems, this paper proposes a brand-new access structure based on multi-valued decision diagram (MDD). According to this access structure, we design a new CP-ABE scheme which performs better than many current schemes. First, our scheme supports multi-valued attributes directly. Second, the size of secret key is constant because it bears no relationship to the number of attributes. Third, the time complexity of decryption stage is O(1).