In order to support the construction of a new power system spot market with high proportion of new energy, it is necessary to establish a spot market mechanism that accurately reflects the space-time balance cost of electricity, form a price signal that measures the value of source-grid load and storage, and stimulate accurate and efficient interaction between source-grid load and storage. When new energy becomes the main power source, the current spot market mechanism will have the following problems: 1) if new energy determines the marginal price, its near-zero marginal cost will lead to the disappearance of the spot price signal, and the price regulation function will no longer exist; 2) if expensive and small amount of flexible resources determine the marginal price, the difference of power supply service between new energy and flexible resources cannot be reflected, and new energy will obtain excessive profits, resulting in the phenomenon of The “ride-sharing” phenomenon. To this end, the article designs an electricity spot market mechanism that decouples new energy and flexibility resources and forms a time-sharing capacity tariff based on the fixed cost of new energy. The new energy timesharing capacity market shares the fixed costs of new energy market players on a day-by-day basis to form a time-series price signal; the spot market for flexibility resources discovers the price of deviated power balance, frequency regulation, standby and other residual power balance services through competition; and ensures that the “whoever incurs the cost bears the cost” principle is satisfied through fair cost sharing to new energy and users. By sharing the costs fairly with new energy sources and users, we ensure that the principle of “whoever incurs the cost bears the cost” is met, and the market mechanism is used to match supply and demand for flexibility.