Abstract: In order to solve the engineering geological problems of the soft rock in the Jurassic Coalfield of northwest China, this paper has carried out mineral composition analysis, swelling test, mudding test, disintegration test and rock mechanics characteristic test, etc., the water-rich environment of the weak rock mass is analyzed, the concept of weak cementation swelling water-rich soft rock deterioration effect is defined.Based on the engineering geological characteristics of soft rock, the traditional method of controlling the deformation of surrounding rock solely by means of support is changed, the internal causes and inducement of soft rock deterioration are analyzed, and the key element of water-rich environment is grasped, this paper puts forward the prevention and control concept of "treating soft need to treat water first", the soft rock engineering degradation control technology system of "large water prevention and control, small water management, strengthening support and collaborative governance" have been formed.The technology of "large water prevention and control" solves the disaster of water inrush with mud and sand from the source, "small water management" blocks the contact between water and soft surrounding rock, and "strengthening support" gives full play to the function of support as the basic means of controlling surrounding rock deformation, the principle of "collaborative governance" of water and soft rock is adhered to.The engineering practice has proved the effectiveness of the above-mentioned key technologies for soft rock deterioration control.It also shows that water disaster prevention and soft rock deterioration control must be comprehensively analyzed and coordinated.