As an important part of renewable energy, the development and utilization of offshore wind energy has been widely concerned. The offshore converter stations utilizing modular multilevel converter (MMC) technology face challenges such as large size, high costs, and complex construction. Therefore, exploring cost-effective and reliable transmission solutions for offshore wind energy is crucial. Line-commutated-converter (LCC) may be a better solution for the HVDC sending station with its technological maturity and smaller size of offshore platform. In this article, the mathematical model of grid-forming (GFM) wind farm and LCC-MMC hybrid HVDC transmission system is developed, and the power characteristic equation of the system is deduced. On this basis, a reactive power synchronization control strategy for the GFM wind farm with the LCC-MMC hybrid HVDC transmission system is suggested. By coordinating the multiple wind turbines and LCC, the system can achieve the functions of maximum power delivery and synchronization between wind turbines. Ultimately, the viability of the suggested scheme is confirmed through time domain simulation.