The invention relates to a boiler capable of achieving quick sampling. The boiler is provided with a material inlet, a material outlet and a heating unit, the side wall of the boiler is provided with a sampler, a sampling chamber is communicated with the interior of the boiler, and a sampling hole of the sampler can slide or rotate between the exterior and the interior of the boiler. The portion, close to the sampling chamber, of the head of a sliding chamber of a base body is provided with a first seal ring, the portion, close to the sampling chamber, of the tail of the sliding chamber of the base body is provided with a second seal ring and a third seal ring, the distance between the second seal ring and the third seal ring is larger than the width of the sampling hole, the sampling chamber is isolated from the sliding chamber through the first seal ring, and the sampling chamber is isolated from the outside atmosphere through the second seal ring and the third seal ring. The head end of a sampling rod is provided with a first blind hole, the tail end of the sampling rod is provided with a second blind hole, the sampling hole is isolated from the first blind hole and the second blind hole, and the first blind hole and the second blind hole are communicated through a ventilation channel. Through the design of the blind holes in the sampling rod, the seal effect of the seal rings is improved, and the service life of the seal rings are prolonged; by adopting the two seal rings with the small thread diameter, the pulling force or the pushing force can be reduced when sampling is performed, and therefore the sampling speed is increased.