The invention discloses a nitrogen oxygen sensor adopting an improved structure. A zirconium oxide substrate of the nitrogen oxygen sensor adopting the improved structure comprises a first zirconium oxide ceramic layer, a second zirconium oxide ceramic layer, a third zirconium oxide ceramic layer, a fourth zirconium oxide ceramic layer and a fifth zirconium oxide ceramic layer which are sequentially arranged from the top down in a cascading manner; in the zirconium oxide substrate, a gas inlet, a first chamber and a second chamber are formed between the first zirconium oxide ceramic layer and the third zirconium oxide ceramic layer; a diffusion barrier is arranged between the gas inlet and the first chamber and between the first chamber and the second chamber respectively; an oxygen pump is arranged inside the first chamber; the oxygen pump comprises a main pump electrode and a common electrode; an auxiliary pump electrode and a measuring pump are arranged inside the second chamber; the measuring pump comprises a measuring electrode; a reference electrode is arranged on the lower surface of the third zirconium oxide ceramic layer; the main pump electrode and the auxiliary pump electrode are respectively formed by printing a mixed slurry of platinum, gold, zirconium oxide and a pore-forming agent on the lower surface of the first zirconium oxide ceramic layer and sintering. Through the structural design, the nitrogen oxygen sensor adopting the improved structure has the advantages of a novel design and good stability and reliability; the oxygen pumping capacity of the oxygen pump can be effectively improved, so that the measurement accuracy can be effectively improved.