The invention discloses a method for designing lightning arrester parameters at a connection bus of a hybrid DC high-low voltage converter. According to the method, the parameter design of a first lightning arrester configured on the connection bus between a receiving end high voltage LCC converter and a low voltage VSC converter needs to consider one or more of the following four conditions: designing a first lightning arrester DC reference voltage according to the primary purpose of the first lightning arrester; designing the first lightning arrester DC reference voltage according to the cooperation between the first lightning arrester and a third lightning arrester; designing the first lightning arrester DC reference voltage according to the purpose of protecting a DC circuit breaker bythe cooperation of the first lightning arrester and a second lightning arrester; and designing the first lightning arrester DC reference voltage according to the cooperation between the first lightning arrester and a DC Chopper. One or more of the above conditions are considered, a maximum reference voltage is selected as the reference voltage of the first lightning arrester. According to the method, the protection effect of the first lightning arrester is fully exerted while the first lightning arrester operates safely.