When I sneeze my uterine muscle contrat and stay that way for up to10 minutes. Why is this happening?

Cramp. I assume you are pregnant and therefore concerned about your uterus. When you sneeze, your outside and inside shake accordingly. Your uterus, especially if close to deliver reacts to that by cramping or contracting and that may be something you perceive. Another option could be pain from the ligament supporting the uterus. It is always under stress by supporting it and now from sneezing.