The invention discloses a biological combined synergistic deodorization process and a device thereof. An odor source is humidified and sequentially subjected to microbial filler deodorization and soil deodorization by a two-stage deodorization process, and finally freely escape through the top of a soil deodorization system. The deodorization device comprises a deodorization box, an odor pipeline and a humidifying pipeline, one end of the odor pipeline is communicated with the odor source, the other end of the odor pipeline is connected to an air inlet of the deodorization box, a fan is arranged on the odor pipeline, the humidifying pipeline is parallelly connected onto a deodorization pipeline in front of the fan, connected with a humidifier and used for humidifying odor in the odor pipeline, an air distribution layer, a primary deodorization layer and a secondary deodorization layer are serially connected into the deodorization box, the air distribution layer is communicated with the air inlet, the primary deodorization layer is a microbial filler deodorization system, and the secondary deodorization layer is a soil deodorization system. The structure of a biological deodorization device is adjusted, biological deodorization process features are combined, the multi-stage deodorization system is used for synergistic deodorization, the treatment efficiency of the deodorization system is guaranteed, integration degree is high, and treatment effects are good.