The invention discloses a sensitive data self-adaptive desensitization method and system, and relates to the field of computer technology and information security, and the method comprises the following steps: a plurality of desensitization algorithms is added into a desensitization server, anda one-to-one corresponding quantitative relation between each desensitization algorithm and each desensitization effect in a plurality of desensitization effects is set; the desensitization server receives a desensitization instruction sent by the client device, and reads the original data from the datasource server according to the desensitization instruction; the desensitization server constructs a desensitization effect preference training set of the user for different sensitive data types to form a decision tree; and the desensitization server positions the sensitive data existing in the original data, determines the type of the sensitive data, selects a desensitization algorithm for the sensitive data by using a decision tree, and generates replacement data of the sensitive data according to the desensitization algorithm. The user configuration process is simple, and intelligent automatic configuration and automatic desensitization of the desensitization strategy can be realized.