Abstract: A high pricision combination method for solving BIE of the second kind is presented. The combination algorithm is as follows:Step 1. Compute the j^th(j=1,…,m) Nyström approximate equation with nodes (nj+j)/(mn)_i=1ⁿ parallelly. Step 2. Compute the j^th(j=1,…,m) interior print value by the j^th Nyström solution parallelly. Step 3. Compute the average of m interior point values, which is the combination approximation.It can be proved that the precision of the combination approximation is almost same as the precision of Nyström appximation with mn nodes.