This paper proposes a comprehensive analysis method for levelized costs of energy (LCOE) in tidal current power generation farms (TCPGFs). The detailed investment and operation costs in the life cycles of TCPGF projects are all quantified and incorporated in the calculation of LCOE, including the emission reduction benefits brought by TCPGFs. An annual electricity production (AEP) evaluation technique is proposed, in which the impacts of wake effects, TCPGF reliability and tidal current velocity (TCV) characteristics in the planning sea area are considered. A detailed capital expenditures (CAPEX) model is developed to incorporate all related costs at different stages of TCPGF project. An evaluation model considering the variations of annual operation expenditures (OPEX) is presented. The accuracy of the proposed method is verified using the measured data, which are collected from MeyGen Phase 1A project in UK and two sites located in UK and America.