Aiming at the common problems of poor durability and dry shrinkage performance of traditional inorganic-binder solidified soil, super absorbent polymer (SAP) material was added on the basis of mucky clay reinforced by the inorganic binder. Through the unconfined compressive strength test, compaction test, dry wet cycle test, dry shrinkage deformation test and XRD test, the influence and action mechanism of SAP material on the engineering properties of inorganic-binder solidified soil were analyzed and discussed. The test results show that the addition of SAP material can not only improve the unconfined compressive strength of inorganic-binder solidified soil, but also significantly improve the compactness, durability and dry shrinkage performance. Mechanism analysis shows that SAP material mainly depends on the filling effect to improve the engineering properties of inorganic-binder solidified soil.