Concrete capable of inhibiting and repairing saltpetering of prefabricated duct piece and preparation method of concrete

The invention provides concrete capable of inhibiting and repairing efflorescence of a prefabricated segment and a preparation method of the concrete. The concrete is prepared from the following raw materials in parts by weight: 180 to 240 parts of cement, 30 to 48 parts of silica fume, 150 to 210 parts of blast furnace slag powder, 80 to 120 parts of water, 54 to 80 parts of quartz sand, 32 to 50 parts of limestone powder, 54 to 80 parts of river sand, 5.2 to 8.4 parts of polyethylene fiber and 0.5 to 1 part of polycarboxylate superplasticizer. The method comprises the following steps: weighing raw materials required by the concrete according to required parts by weight, firstly adding the weighed cement, silica fume, blast furnace slag powder, quartz sand and limestone powder into a stirrer, and carrying out dry stirring for 1 minute to obtain a powder mixture; adding the weighed river sand and polycarboxylic acid water reducer into the stirrer, and continuously performing dry stirring for 1 minute; and uni