介绍了模型试验中轴向力的测定、轴流式机组轴向力的一般变化规律、下游水位和机组顶盖补气对轴向力的影响等。提出了导叶全关时机组的负轴向力与下游水位的关系可按费洛德数相等进行原模型换算；机组甩负荷时，顶盖补气能有效地减小抬机力和转速升高：以及在数值计算中应以模型实测轴向力持性为基础建立数学模型计算水轮机动态过程中轴向力的变化规律才能有足够的精度，否则将造成较大的误差而无实用价值． The measurement of axial force in model test, the general variation rule of axial force of axial flow unit, the effect of downstream water level and gas supplementing of cap on the axial force are introduced. The relationship between the negative axial force and the downstream water level when the guide vane is fully closed can be calculated according to the Equalization of the Fellows number. When the unit is off load, the cap gas supplement can effectively reduce the lift capacity and speed High: And in the numerical calculation should be based on the measured axial force model to establish a mathematical model to calculate the dynamic process of turbine axial force variation law to have sufficient accuracy, otherwise it will cause greater error without practical value.