The invention discloses a needle position detection device and a color changing box. The needle position detection device is connected to a rotating part for driving a needle plate and comprises a gear set and a sensing chip, the gear set comprises a starting-end gear and a final-end gear, the starting-end gear and the final-end gear are in meshed connection, the rotating part is fixedly connectedto the center of the starting-end gear, the final-end gear is provided with a sensing part, and the sensing chip senses changes of the sensing part to detect rotating turns of the final-end gear. Bythe needle position detection device and the color changing box, needle position detection is realized through the simple structure.