The invention relates to a double 
reverse flotation process of middle-low grade 
phosphorite. The double 
reverse flotation process is characterized by comprising the following steps of: after milling raw 
phosphorite ores to the 
granularity required by flotation, adding a 
reverse flotation de-magging adjustor and a catching agent for executing rough 
magnesium flotation operation, wherein de-maggingrough concentrate is in a rough 
magnesium flotation groove; after adding the 
regulator in rough 
magnesium flotation foam, executing magnesium recleaning operation, wherein de-magging middling productis in a magnesium recleaning groove and the magnesium recleaning foam is 
carbonate gangue; adding a de-silication 
disperser and a de-silication catching agent in ore 
slurry in the groove after de-magging, and carrying out de-silication rougher flotation operation I; then adding a de-silication catching agent and non-polar oil for performing the de-silication rougher flotation operation II, wherein 
ore concentrate is in a rough 
silicon flotation groove; after combining the foam of the 
silicon rougher flotation I and the 
silicon rougher flotation II, adding the de-silication catching agent for performing the silicon recleaning, wherein de-silication middling product is in a silicon recleaning groove, and silicon recleaning foam is silica 
gangue; and combining the de-silication middling product and the 
ore concentrate to obtain the comprehensive 
phosphorus concentrate. The process can increase the catching of the silicon 
gangue, improve the selecting efficiency and reduce the consumptionof the reverse flotation de-silication catching agent.