In view of the structure characteristic of the force of the load and the transmission force on tristrut connected landing gears, holistic load calibration but regressing loads modal respectively test method are adopted for the first time, the three struts landing gears are installed and loaded as one, and the effect problem among the struts loads are resolved successfully. With loads and structure analysis, strain gauges and loads cases are designed for the struts with I -shaped section and large obliquity, and loads cases include single strut cases, as well as combination loads cases of two or three struts. General reference coefficient of multi-strut is put forward to analyze the effect among the struts loads. The result indicates that the loads are transferred forwards, the latter one affects the proximate front one, but the front one doesn't affect the latter one. In terms of this result, the policy of regressing loads modal is put forward which is regressing loads modal respectively and calculating struts loads one by one, then deducting the influence between struts according to the general reference coefficient. The test method is impactful and the loads modals meet the needs of precision.