The invention discloses a volatile organic compound (VOC) collecting system used in the wood heat treatment process and a collecting method utilizing the VOC collecting system. The VOC collecting system comprises a heat treatment device, a gas condensation device, a gas drying device, a VOC absorption device, a gas circulation device and a deoxygenation device which are sequentially connected through connecting pipelines. The VOC absorption device is composed of a VOC liquid phase absorption device and a VOC solid phase absorption device which are connected in series and used for absorbing VOC released in the heat treatment process. The VOC released by wood heat treatment is cooled and dried and then enters the VOC absorption device. After the VOC is collected, residual gas returns to a wood high-temperature heat treatment device through the deoxygenation device, and circulation is conducted until the VOC is completely absorbed. The VOC collecting system is simple, the collecting method enables operation to be convenient, process conditions are easy to control in the collecting process, and the collecting system and method are suitable for collecting released VOC of various types of wood under different heat treatment conditions.