Block chain information classification and sharing method and system

The invention discloses a block chain information classification and sharing method, comprising the steps of setting security levels of to-be-encrypted block chain information, wherein the to-be-encrypted block chain information comprises user information, evidence information and settlement information; encrypting the to-be-encrypted block chain information through utilization of public keys of which security levels are the same as those of the to-be-encrypted block chain information, thereby acquiring encrypted ciphertexts of corresponding security levels; storing the encrypted ciphertexts to encrypted information items of which security levels are the same as those of the encrypted ciphertexts; acquiring the encrypted ciphertexts from the encrypted information items; and decrypting theencrypted ciphertexts of which security levels are the same as those of private keys through utilization of the private keys. The information with different important degree and security requirementsis encrypted respectively