A converter parameterized constant admittance modeling method based on a cross initialization including the following steps: (1) performing parameterized modeling on a converter, wherein switches are modeled using a parametric historical current source constant admittance model and other components are modeled using a traditional electromagnetic transient simulation integral model in the converter; (2) detecting whether state switching occurs, performing cross initialization correction when occurring; (3) determining model parameters, and establishing an equivalent admittance matrix and an injection current source of a whole grid, to obtain an electromagnetic transient simulation equivalent model; (4) solving a network tide according to a basic solving equation I=YU to obtain an electromagnetic transient model simulation result of the converter at current time; and (5) calculating an equivalent admittance matrix and an injection current source at next time through a current network state quantity, and returning to step (2) until a simulation terminates.