The invention relates to a preparation method of a nano-hydroxyapatite/nano-hydroxyapatite gas sensing material. The preparation method comprises the following steps: first, preparing a graphene oxide dispersion liquid by an ultrasonic method; preparing hydroxylated modified graphene through reduction and modification of a mussel foot fibronectin analogue; in-situ reducing nucleation and growth of nucleation by a chemical precipitation method; and centrifugalizing, washing and drying to obtain the nano-hydroxyapatite/nano-hydroxyapatite gas sensing material. A gas sensor element can be prepared by the following steps: preparing the obtained gas sensing material with a binder to slurry; coating the slurry on a base body with an electrode; and then, sintering and welding for 3 hours at 300 DEG C under a nitrogen protective atmosphere.