The invention provides a concentrated price bidding and trading system and a method for electric power market trading, which belong to the electric power market trading system technology field. The method comprises the steps of user log-in, declared information input, price difference calculation, pre-traded result calculation and trade verification. The concentrated price bidding and trading system proposed by the invention is high in reuse and extendibility and can be used for electric power trading in terms of day, month and quarter. With the system of the invention, the seller and buyer can trade on the same platform and can effectively promote the fair, transparent, and regulated trading among all parties of the market. The market supply and demand balance can be maintained; and the electric power system can be run more stably and safely.