The invention provides mud for drilling construction and a drilling construction method. The mud is prepared from components in parts by mass as follows: 7-15 parts of bentonite, 4-7 parts of sodium carbonate, 0.4-1.5 parts of a water reducer and 100 parts of water. According to the mud, the water reducer is added to a mud formula, the use amounts of bentonite and water are reduced by 50%-60% and25%-35% respectively; the use amount of the bentonite is reduced, manpower and material resources in the mud preparation process are effectively saved, and influence on the environment is reduced; through the proportion relation between reduction of the water use amount and components, the flowability of the mud can meet the construction requirement, the mud density is increased, the wall protection effect is enhanced, and mud loss is reduced. With the adoption of the provided mud, the construction safety grade is further increased.