Gradually, anchor is in the working state of tension, but its stress becomes rather complicated when influenced by some external factors such as water, ground loads, etc. Aiming at the problems that ground additional load or coupling action of water and the additional load are forced on soil slope, the axial strain distributions of anchor tendons were obtained by model test. The change rules of axial strain at anchor head, near to slip plane, and end of the anchorage were analyzed respectively. The results show that under ground loads, the strain of anchor is biggest at the anchor head, and it gradually decreases from outer to inner. Under combined water and ground load, the stress state of the anchor system changes from tension to bending, and the upper anchors are most urgently affected. The experimental results can supply a reference for design and research of soil anchor with similar conditions.