A fast sampling and analyzing system comprises a sampler, a negative pressure device, a conveying pipeline, a separator, a sample sending device and a detecting device. The sampler, the conveying pipeline, the separator and the negative pressure device are in sequential connection, and the sample sending device is positioned below the separator and the detecting device and capable of moving between the separator and the detecting device. The invention further provides a method for sampling and analyzing by adoption of the system. By organic combination of sampling, sample sending and detecting, sample analysis can be realized by local micro cutting of samples, intrinsic morphological characteristics can be ignored, and pretreatment of to-be-tested samples is avoided. Therefore, the fast sampling and analyzing system and the method have advantages of high automation degree, quickness in response and zero pollution.