Annulus fracturing combined with hydraulic fracturing and coiled tubing has become an effective method for shale reservoirs. However, during annulus fracturing, sand-carrying fracturing fluid will cause abrasion on the outer wall of CT, especially in spiral and normal winding sections. The abrasion of coiled tubing outer wall in annulus fracturing process was simulated by software. Based on the analysis of flow field and abrasion law, the relationship between sand carrying fluid flow rate and abrasion and the specific position of the most serious abrasion are obtained. It provides technical support for selecting suitable operation parameters to reduce erosion wear of tubing and casing wall under fracturing conditions.