The invention discloses a highway temporary parking warning device. The highway temporary parking warning device comprises a support, a parking warning indicator, a reflection board combination, a solar cell combination and an antenna; the parking warning indicator comprises an infrared communication module, an ultrasonic radar and an emergency help-seeking button; the infrared communication module is used for being in communication with an infrared communication handheld machine and setting parameters; the ultrasonic radar is used for detecting temporary parking; the reflection board combination is rotated by a certain angle, and then a safety warning area is arranged behind the temporary parking area; the emergency help-seeking button is used for allowing temporary parking driving personnel to send out emergency help-seeking information; the antenna is used for communication among the highway temporary parking warning devices; the highway temporary parking warning devices are fixedlyarranged at the two sides of a highway at equal intervals and are operated in a linkage mode; and the ultrasonic radar is used for detecting temporary parking in an emergency lane and controlling therotating of a reflection board in 150 meters or 250 meters behind the temporary parking area to form the safety warning area, so that collision accidents of a rear vehicle and a fault vehicle parkedin the emergency lane are prevented.