The invention belongs to the field of feeding devices of flowing objects needing to be packaged and particularly discloses a fertilizer packaging machine. The fertilizer packaging machine comprises a support and a hopper. The hopper is fixed to the support. A conveyor belt is arranged below the hopper. The machine further comprises a controller, a tension sensor and a sealing machine. A discharging port is formed in the lower portion of the hopper, obliquely arranged and connected with a controllable valve and packaging bags. The tension sensor is fixed to a rack. The tension sensor and the controllable valve are connected with the controller respectively. The discharging end of the conveyor belt is connected with a chute. The other end of the chute is connected with the sealing machine. By the adoption of the fertilizer packaging machine, fertilizer directly flows into the packaging bags, it is guaranteed that the mass of the fertilizer in all the packaging bags is the same through the tension sensor, openings of the packaging bags are directly sealed through the sealing machine, the fertilizer is prevented from falling onto the conveyor belt and splattered out of the conveyor belt, and the fertilizer is prevented from being wasted.