The invention relates to a soil in-situ repairing agent used for synchronous treating heavy metal pollution and organic pollution. The soil in-situ repairing agent includes a mixture A and a mixture B, wherein the mixture A comprises following components, by mass, 100 parts of Hangjin 2# soil, 10-30 parts of activated charcoal, 20-50 parts of cement and 2-5 parts of an organic flocculant; and the mixture B comprises at least three of following components, by mass, 16-32 parts of sodium thiosulfate, 16-32 parts of ferric oxide, 48-96 parts of calcium sulfate, 32-80 parts of aluminum sulfate and 16-32 parts of an alkali metal carbonate. The soil in-situ repairing agent can eliminate bio-availability from heavy metals, such as cadmium, chromium, mercury, lead, arsenic, nickel, zinc, copper, manganese and vanadium. Meanwhile, the soil in-situ repairing agent can degrade and adsorbingly remove organic pollutant in soil and can enable soil after being repaired is stable in aggregate. The soil in-situ repairing agent allows soil to have strong water-retaining property, breathability and water permeability.