Present simulation models used to analyze MMC-HVDC are limited, there is no a model which is suitable for all situations. This paper takes detail model, accelerated model and wide-band model as lessons, and acquires a multi-dimension model about modular multilevel converter. It has one sub-module as a detail model and the other sub-modules accelerated model per arm. It also considers the effect of stray elements of real system by accessing the stray elements to the right positions. This model has the ability of device level electromagnetic transient simulation, and has the characteristics of high-efficiency and high-accuracy, so it could meet all the demand when the MMC-HVDC is simulated. A two-terminal simulation model of MMC-HVDC is built in PSCAD/EMTDC. It turns out that the multi-dimension model of modular multilevel converter is correct and effective.