The invention discloses a photovoltaic array foundation strength detecting method. The photovoltaic array foundation strength detecting method is characterized by comprising following steps: firstly,stand columns used for supporting a photovoltaic plate and a photovoltaic support are fixed to a concrete foundation, and tilting moment borne by each stand column is calculated out; secondly, adjacent stand columns in the north and south directions are effectively connected with one ends of steel wire ropes within the range away from the tops of the stand columns by 50 mm to 100 mm; thirdly, a lever pulley block with display force numerical value is used for being connected with the other ends of two steel wire ropes; fourthly, force is applied to the two stand columns gradually, whether thestand columns collapse or incline or are not obviously shifted is judged, if force is applied to the two stand columns until the force numerical value displayed on the lever pulley block is the same with the numerical value of the calculated tilting moment, and the stand columns do not tilt, incline or are not obviously shifted, it explains that the strength of a concrete foundation meets the design requirements. The pull method can reduce investment of process monitoring resources, the opposite pulling method is used for checking the two foundations at one time, and the efficiency is improved.