Web UI test cases are used for the automatic testing of web applications. When a web application is updated, these UI tests should also be updated for regression testing of the new version of web application. With the rapid evolution, updating UI tests is a tedious and time-consuming task. To solve these problems, automatically repairing web UI tests has gained increasing attention recently. To repair web UI tests, the most important step is to match the UI elements before and after the web page update. Existing work matches UI elements according to visual information, attributes value, or Document Object Model (DOM) structures. However, they either achieve low element matching accuracy or only work on simple UI tests. To solve these problems, we proposed UITestFix, an approach based on a novel iterative matching algorithm for improving the accuracy of matching UI elements. UITestFix is designed based on two main insights: (1) beyond attribute and DOM structures, the relations between different elements can also guide the matching process, and (2) the matching results of previous iterations could guide the matching of the current iteration. Our evaluation of publicly available datasets and two industrial apps shows that UITestFix outperforms four existing approaches by achieving more accurate element matching and producing more correct fixes.