The invention provides hollow micropore inorganic heat insulation mortar, which is prepared from the following ingredients in parts by weight: 40 to 60 parts of ordinary portland cement, 5 to 10 parts of silica fume, 10 to 15 parts of nickel slag powder, 25 to 35 parts of expanded perlite micro powder, 0.1 to 1 part of re-dispersible emulsion powder, 0.1 to 1 part of hydroxypropyl methylcellulose and 0.1 to 1 part of polypropylene fiber. The hollow micropore inorganic heat insulation mortar has the advantages that the heat insulation performance is good; the construction performance is good; excellent performance such as cracking resistance, hollowing resistance, fireproof function and low cost is achieved.