To get unthickened miscellaneous poly indica drilling fluid, studied is the performance of low solids fluids of basic slurry containing polysaccharides (KD-03) and different types of hydrolyzed polyacrylonitriles in laboratory experiment and test are such performance parameters as density, viscosity, conductivity and filtration of the drilling fluid prepared with different amount of three types of hydrolyzed polyacrylonitriles. It is found that the compatibility of KD-03 system with such hydrolyzed polyacrylonitrile is desirable and they can compose an unthickened drilling fluid system and its viscosity is obviously low than hydrolyzed polyacrylonitriles and various performances are improved obviously.