The invention discloses an environment-friendly interior wall putty powder and putty paste and a preparation method thereof. The putty powder includes the following components in parts by weight: 45-72 parts of talcum powder, 18-30 parts of heavy calcium carbonate, 5-10 parts of calcium-based bentonite, 0.6-1.5 parts of sodium carboxymethyl cellulose, 1-5 parts of polyacrylamide, 0.3-1.7 parts of hydroxyethyl cellulose; 0-20 parts of building gypsum powder, carboxymethyl cellulose 0-0.8 parts, 0-8 parts of α-pregelatinized starch, 0-3 parts of hydroxypropyl methylcellulose, and 0-0.5 parts by weight of sodium dodecylbenzenesulfonate. The preparation method of the putty powder is to mix the above-mentioned components evenly, and then discharge after stirring for 10-15 minutes. Add 0.3 to 0.5 times the weight of the putty powder and water into the putty powder and stir evenly to obtain the putty paste. The putty powder / putty paste of the present invention does not contain or only contains a small amount of formaldehyde, and the content of heavy metal elements is extremely low, which belongs to the green environmental protection product; it has excellent impact resistance, excellent hydrophobicity and water resistance, high elasticity, and good crack resistance performance, storage stability and easy construction.