The utility model discloses a portable formaldehyde detector, relate to building environment formaldehyde detector, by two frame bodies, four telescopic links, five blocks of glass boards, test paper and feed liquor pipe constitute, four angles of frame body all are equipped with adapter sleeve, the both ends of telescopic link are connected respectively on two frame bodies and to be formed a cube framework on the relative adapter sleeve in position, before cube framework, the back, a left side, the right side is all inlayed with the top surface and has been adorned glass plate -type one -tenth closed box, one of them is installed and is equipped with the tube hole on the glass board on the frame body, the feed liquor pipe passes the tube hole and stretches into in the closed box, the inside of closed box is equipped with the base, be equipped with test paper on the base. The utility model discloses a portable formaldehyde detector, for dismantled and assembled structure, its cube framework who comprises frame body and telescopic link, its volume are 1 cubic metre, can be with detecting on liquid slowly flows test paper, test paper shows that the reaction accomplishes the back, can mark down the quantity of detection liquid, can calculate unit volume formaldehyde content.