What should I do if two cities pay social security at the same time?

Legal analysis: you can apply to the relevant departments for merger and transfer.

Legal basis: Article 19 of the Social Insurance Law of People's Republic of China (PRC), if an individual is employed across the overall planning area, his basic old-age insurance relationship will be transferred accordingly, and the payment period will be calculated cumulatively. When an individual reaches the statutory retirement age, the basic pension is calculated in stages and distributed uniformly. Specific measures shall be formulated by the State Council.