The invention discloses a novel CAR (Chimeric Antigen Receptor) and application of novel CAR modified T cells for treating cancer. The novel CAR is formed by an extracellular signal peptide, an antigen binding structural domain, an intracellular first conduction structural domain and an intracellular second conduction structural domain, and contains an intracellular first conduction structural domain NKp44 or an intracellular first conduction structural domain TREM1. According to the novel CAR disclosed by the invention, multiple CAR nucleotide sequences are separated and purified, and the CARand CAR-T cells which specifically aims at CD19 malignant hematologic tumor and mesothelin malignant solid tumor antigens. In a hematologic tumor and solid tumor killing test, the killing capacity ofthe CAR-T cells to tumor cells is obviously enhanced, and good safety and good anti-tumor activity in clinic application are expressed.