This is a study for patients who have been previously treated for NHL. The purpose of this study is to determine the safety and feasibility of double-target CART-19 and 20 cells to the patients with relapsed and refractory CD19+/CD20+ NHL.

Inclusion Criteria:

1. Age between 18 to 75 years old (including 18 and 75)
2. Diagnosed as R/R NHL
3. CD19/CD20 positive confirmed by cell flow cytometry or immunohistochemistry
4. Having at least one measurable lesions
5. World health organization-Eastern Cooperative Oncology Group Performance Status (ECOG) 0-2
6. Life expectancy no less than 3 months
7. enough main organ function
8. Pregnancy test within 7 days must be negative for women of childbearing period, and appropriate measures should be taken for contraception for women in childbearing period during the study and 12 months after this study
9. Agreeing to sign the written informed consents

Exclusion Criteria:

1. Congestive heart failure, uncontrolled coronary heart disease, arrhythmia and heart infarction less than 12 months
2. Active GVHD
3. History of severe pulmonary dysfunction
4. Active malignant tumor need be treated at the same time
5. Uncontrolled active acute/chronic infection
6. Severe autoimmune diseases or congenital immunodeficiency
7. Untreated active hepatitis
8. HIV-positive, AIDS patients and syphilis infection
9. History of severe allergies to biological products
10. Patients with a history of mental illness
11. Pregnant or lactating women; (female participants of reproductive potential must have a negative serum or urine pregnancy test)
12. Researchers think of that does not fit to participate in the study, or other cases that affect the clinical trial results