The present invention discloses an inter-trusted-computing-system binding method based on hardware security unit, comprising steps of: configuring binding requirements for hardware security units of trusted computing systems; exchanging hardware security unit information between the hardware security units of the trusted computing systems to be bound, and checking device validities of the counter-party hardware security unit; and if passing the validation check, it continues to the following steps; otherwise, exiting the binding procedure; respectively verifying whether the binding meets their respective binding requirements by the hardware security units of the trusted computing systems to be bound; and if passing the verification, it continues to the following steps; otherwise, exiting the binding procedure; and respectively storing platform information and hardware security unit binding information by the hardware security units of the trusted computing systems. The present method provides a processing mechanism based on hardware security unit in order to establish trusts between trusted computing systems.