The present invention relates to a service system for supporting the maintenance of a value of a non-resident equity and a method thereof and, more particularly, to a system for supporting the maintenance of a value of a non-resident equity and a method thereof, capable of increasing the liquidity of a fund inputted to real estate by paying the non-resident equity issued through a trust company to divide the real estate, which a user trusts, into a resident equity and the non-resident equity for issuing the non-resident equity to a non-resident equity-related account of an owner and providing a joint pool service to support the purchase of the goods and services of a seller using the corresponding non-resident equity as standard money and providing a market using the non-resident equity by supporting share adjustment. Accordingly, the present invention can promote residential stability and economic activation.(20) Trust company(40) Joint pool service(50) Service operation company(A1, A2, A3) Housing securities(BB) Periodic equity(CC) Trust(DD) SellerCOPYRIGHT KIPO 2018