The invention relates to a continuous positive and negative sand washing device for an oil-
water well, in particular to a continuous positive and negative integrated sand washing device for an 
oil well. The device consists of an operation 
machine, pipelines, a sand washing 
pipe, an 
elevator, a pump 
truck and the like, wherein a self-sealing 
wellhead is arranged at the upper end of a big four-way joint of the 
wellhead; the lower end of a sand washing 
pipe column is provided with a sand 
washer, and the upper end of the sand washing 
pipe column is provided with a 
reversing valve; the sand washing pipe column enters a well casing under the well through the self-sealing 
wellhead and the big four-way joint; a three-way valve is connected with a water hose and the self-sealing wellhead and is connected with a positive and negative sand washing regulation and control valve 
bank; the positive and negative sand washing regulation and control valve 
bank is in threaded connection with the pipelines respectively connected onto the pump 
truck, a foul solution cylinder, the three-way valve and the big four-way joint; the three-way valve realizes continuous sand washing operation in the process of carrying out continuous single-length sand washing and carrying out subsequent single-length sand washing by cooperation of the opening and closing of pairs of pipe lines with the 
reversing valve and the self-sealing wellhead; and the positive and negative sand washing regulation and control valve 
bank completes conversion by adjusting and aligning with four holes which are vertical in pairs on a valve core and eight holes on a valve body, so that the positive and negative continuous sand washing operation is realized.