The invention discloses a method for generating a variable parameter chaotic signal, and a chaotic secure communication system. The method comprises the following steps: firstly, chaotic mapping is used to generate the chaotic signal; then a parameter set of the chaotic mapping is determined in advance, so as to process any pseudorandom signal, and enable the state of the pseudorandom signal and the elements of the parameter set to be in one-to-one correspondence; and a corresponding parameter is chosen to generate the variable parameter chaotic signal by chaotic mapping according to the state of the pseudorandom signal. The system comprises a chaotic signal generating module, an analog-to-digital conversion module, a parameter transformation module, a coding module, a multi-path choice switch, an encryption/decryption module, an encrypted message data cache, a plaintext data cache and a control module. The invention can increase the complexity of the output of the chaotic signal or a chaotic sequence, and effectively resist the analysis of the nonlinear prediction technology based on phase-space reconstruction. The output digital chaotic sequence can be taken as a pseudorandom number sequence or key stream to encrypt data; the output continuous chaotic signals can be used for designing a secret communication system based on chaos synchronization .