It’s difficult to obtain the time varying wear of abrasive water jet nozzle by using traditional methods due to its long-hole structure. In order to observe the wear intuitively and instantly, a new kind of nozzle which could be opened along the axis was designed. The wear experiment of 35 millimeter-long nozzle was conducted and the relationship between the nozzle wear and time was obtained. The experimental results showed that the inner face wear of the nozzle firstly happened at the junction between the convergent and straight sections and then successively happened at the sections which are respectively 5 to 10 mm and 20 to 22 mm from the junction.One typical cross section was selected from each section mentioned above to analyze the chamber diameter change varying with time and the reason why the wear of each cross section is different at different time. The analysis on the influence of nozzle wear on cutting ability demonstrated that the abrasives deflect seriously after the wear at the range which is 5 to 10 mm from the junction between convergent and straight sections develops to a certain extent, which makes the cutting ability decline and the nozzle unavailable. It was indicated that the section 5 to 10 mm from the junction is the key position to lengthen the service life of the nozzle.
