Abstract: In the context of the dual carbon target, the “new energy+energy storage” joint system is rapidly developing in a multi-market coupled trading environment. Energy storage devices are not only used to suppress the deviation of new energy output, but also crucial in frequency regulation and peak shaving services in the auxiliary service market. To fully leverage the flexibility of energy storage in a multi-market trading environment, this paper proposes a multi-market coupled bidding strategy for a combined solar energy storage system that takes into account carbon reduction benefits. Firstly, considering the deviation of photovoltaic prediction, a deviation assessment is carried out; Secondly, considering the benefits of China certified voluntary emission reduction（CCER) in the coupled carbon trading market and the benefits of green electricity in the green electricity market, a mathematical model is established with the objective function of maximizing the total benefits of the solar energy storage joint system in the energy market, auxiliary service market, and carbon market, and solved using the CPLEX solver. Through case analysis, it is shown that the participation of the photovoltaic energy storage joint system in the bidding method of multi-market coupling increases the system revenue by 11.6% and 10.5% respectively compared to participating in the carbon market or green electricity market alone. The energy storage devices configured in photovoltaic are also fully utilized.