The invention relates to a deslagging and dephosphorizing method of an electric stove, which adopts the following public technical scheme: slagging; deslagging for the first time; smelting by blowing oxygen, starting to deslag when the temperature of molten steel increases to 1500-1510 DEG C, and controlling the weight percentage of phosphorus to decrease to be not more than 0.015 percent; slagging for the second time; deslagging for the second time, i.e. starting to deslag for the second time when the temperature of molten steel increases to 1520-1550 DEG C, and controlling the weight percentage of the phosphorus to decrease to be not more than 0.010 percent; slagging for the third time; deslagging for the third time, and controlling the weight percentage of the phosphorus to decrease tobe not more than 0.005 percent; slagging for the fourth time; and preserving heat by blowing oxygen, adopting steel and slag residual operation with a tapping amount accounting for 85-90 percent of the total capacity of the molten steel in a ladle, and forbidding slagging in a tapping process. By the method, the content of the phosphorus element in steel can be decreased to be below 0.002 percent, ultra clean soldering steel satisfying the requirement of users can be produced, a path for producing clean steel is provided for manufacturers without the pretreatment of the molten steel, and increase in investment is also not needed.