A foldable portable metal detector, comprising: a detection coil disk; a waterproof circuit protecting chamber; a circuit component comprising a circuit board; folding fixing components; fastening components; an extending rod; a BLUETOOTH module disposed on the circuit board;and a BLUETOOTH remote control component; wherein the BLUETOOTH module is fixedly installed on the circuit board and is electrically connected with the circuit board;the BLUETOOTH remote control component is configured to control the foldable portable metal detector; the circuit component is fixedly disposed in the waterproof circuit protecting chamber; the circuit component is withdrawnable from the waterproof circuit protecting chamber; the extending rod is fixedly connected to a tail end of the waterproof circuit protecting chamber; the extending rod is manually detachable from the waterproof circuit protecting chamber; the circuit component is electrically connected with the detection coil disk; brackets are disposed on the detection coil disk; each of the brackets comprises a first through hole and a second through hole; the fastening components comprise each a bolt and a fixing column; connecting heads are disposed on the waterproof circuit protecting chamber; connecting holes are on the connecting heads; each bolt passes through a connecting hole and a first through hole associated with the connecting hole in sequence; the bolts are movably connected to the folding fixing components; each fixing column passes through a second through hole; the waterproof circuit protecting chamber rotates with the bolts as a rotation axis. a detection coil disk; a waterproof circuit protecting chamber; a circuit component comprising a circuit board; folding fixing components; fastening components; an extending rod; a BLUETOOTH module disposed on the circuit board;and a BLUETOOTH remote control component; wherein the BLUETOOTH module is fixedly installed on the circuit board and is electrically connected with the circuit board;the BLUETOOTH remote control component is configured to control the foldable portable metal detector; the circuit component is fixedly disposed in the waterproof circuit protecting chamber; the circuit component is withdrawnable from the waterproof circuit protecting chamber; the extending rod is fixedly connected to a tail end of the waterproof circuit protecting chamber; the extending rod is manually detachable from the waterproof circuit protecting chamber; the circuit component is electrically connected with the detection coil disk; brackets are disposed on the detection coil disk; each of the brackets comprises a first through hole and a second through hole; the fastening components comprise each a bolt and a fixing column; connecting heads are disposed on the waterproof circuit protecting chamber; connecting holes are on the connecting heads; each bolt passes through a connecting hole and a first through hole associated with the connecting hole in sequence; the bolts are movably connected to the folding fixing components; each fixing column passes through a second through hole; the waterproof circuit protecting chamber rotates with the bolts as a rotation axis.