Abstract: Considering the uncertainty of large-scale wind power under the condition of long-distance AC-DC hybrid transmission.Power fluctuation of the power grid at the sending and receiving ends.An optimization method of transmission capacity allocation based on energy transmission path optimization of AC-DC system is proposed.Firstly,taking the head and end of AC-DC transmission lines as nodes and AC-DC transmission lines as edges,the model of AC-DC energy directional transmission network is established.Secondly,the power dispatch propagation intensity（PDPI） model is established by analyzing the load degree of AC-DC transmission capacity and wind power uncertainty in hybrid grid.On this basis,an optimization model of wind power fluctuation power flow propagation path based on the minimization of propagation intensity is established.Then,the relationship between the optimal propagation path and the power flow distribution in the simultaneous interpreting of the wind power node fluctuation in the directed propagation network of the AC-DC hybrid power system is studied.An AC-DC power flow optimization method based on the improved ant colony algorithm is constructed.Finally,based on the actual operation data of a four province AC-DC interconnected power system,an optimal simulation model of ACDC transmission capacity allocation is established.The simulation results show that the AC-DC capacity optimization method based on the transmission capacity variation propagation intensity is proposed It can effectively reduce the influence range of wind power uncertainty fluctuation on AC-DC power grid,and has good calculation accuracy and solution speed.