The invention relates to a formula and preparation method of a 200 DEG C temperature and salt resistant drilling fluid with strong inhibition and high density. The formula is characterized in that in the formula, a high temperature salt resistant shear strength improving agent is a silicate modified substance; fluid loss additives A and B are products with carbon-carbon chains main chains and sulfonic acid groups, pyrrolidone groups or alkane groups as branched chains; an inhibiting/anti-collapse agent is a modified natural vegetable pitch derivative with a high softening point; an inhibiting/lubricating agent is a high polymer nonionic surfactant; and a water soluble heavy weight additive is a compound of low carbon organic acid salts of alkali metals, organic acid ammonium and organic acid quaternary ammonium. The preparation method is characterized by successively adding corresponding components with determined concentrations to the fresh water at a certain stirring speed according to the formula, thus obtaining the drilling fluid. The formula and the preparation method have the following beneficial effect: the problems of difficulty in control of viscosity, high fluid loss, low solid phase capacity and poor pollution resistance of the drilling fluid with high density are solved.