A new integrated design scheme for high-voltage line and reactor protection suitable for offshore wind power transmission lines is proposed to address issues such as harsh operating environment, limited platform area resources, and significant capacitive current in cable lines. First, considering the transmission line and reactor as a piece of electrical equipment, an integrated optimization scheme is designed to avoid the traditional iterative calculation of reactor branch current. Then, a comparative study is conducted on the compensation effect of traditional and traveling wave differentials on the capacitance current of cable lines, and an optimized processing technology for line protection is proposed. By introducing a more suitable line zero sequence current as the braking current for the zero sequence differential of the reactor, an optimization strategy for the reactor protection function is proposed. Finally, simulation experiments have verified that the proposed optimization processing technology can improve the sensitivity and reliability of differential protection for submarine cable lines and zero sequence differential protection for reactors.