The utility model discloses a steel truss assembling support, and relates to the field of bridge construction. The steel truss assembling support is arranged on land or in water, and comprises pile foundations, a vertical and horizontal direction connecting system, a pile top distributive girder and a construction platform, wherein the pile foundations are connected through the vertical and horizontal direction connecting system; the tops of the pile foundations are provided with the pile top distributive girder; the construction platform is arranged on the top of the pile top distributive girder; according to the steel truss assembling support, a temporary supporting point is arranged at each lower chord node of a steel truss; each temporary supporting point and each steel truss assembling node are integrally deviated towards the north by a half internode. The steel truss assembling support is assembled ashore, a condition is provided for factorization, adverse effects on steel truss welding and high-strength bolt screwing quality brought by rainy season and winter are reduced, the construction progress can be accelerated, the construction cost can be reduced and the quality can be effectively guaranteed.