Inclusion Criteria:  The age is 18 years old and above; Patients with thymic cancer confirmed histologically (WHO classification), including all subtypes; Inoperable advanced disease (Masaoka-Koga staging), which progresses after receiving at least one systemic chemotherapy; Volunteer to participate in this clinical trial, understand the research procedures and be able to sign written informed consent; ECOG performance status (PS) level 0 to 1; Estimated survival time ≥ 3 months; According to the RECIST1.1 standard, the patient has at least one measurable lesion; Be able to provide tissues from archive tissue samples or newly obtained core or excision biopsy tissues of tumor lesions; According to the judgment of the investigator, it can comply with the test plan; Past anti-tumor therapy (including chemotherapy, radiotherapy, biological therapy, endocrine therapy, targeted therapy, immunotherapy) from the end to the first use of the study drug washout period ≥ 4 weeks, including oral fluorouracil and small molecule targeted drugs Washout period ≥ 2 weeks;  Good organ function level:  Bone marrow function needs to meet:  Absolute neutrophil count (ANC) ≥1.5×109/L; Platelet count (PLT) ≥80×109/L; Hemoglobin (Hb) ≥9 g/dL;  Liver function  Serum total bilirubin (TBIL) ≤1.5 x ULN (except for Gilbert syndrome, total bilirubin ≤2.5 x ULN); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3.0×ULN (or recorded liver transfer: 5.0×ULN);  Kidney function  • Serum creatinine clearance rate (CrCl) ≤1.5 x ULN OR ≥60ml/min (calculated according to Cockcroft-Gault formula);  Coagulation function  • International normalized ratio (INR) ≤ 1.5 × ULN, unless the subject is receiving anticoagulant therapy, as long as the PT or PTT is within the expected therapeutic range of the anticoagulant; activated partial thrombin time (APTT) ≤ 1.5 × ULN, Unless the subject receives anticoagulant therapy, as long as the PT or PTT is within the expected therapeutic range of the anticoagulant;  Heart function • Ejection fraction (LVEF) ≥50%; Fridericia method corrected QT interval (QTcF) male <450ms, female <470ms.  Exclusion Criteria:  Suffer from thymic cancer that can be cured by surgery or radiation; Those who have used anti-tumor drugs targeting PI3Kδ have progressed (such as being out of the group due to intolerance) outer); Suffer from ongoing malignant tumors or other malignant tumors that require active treatment. Skin base Bottom cell carcinoma, except for squamous cell carcinoma of the skin or cervical cancer in situ after potential treatment; Known active central nervous system (CNS) metastasis/cancerous meningitis. Previously accepted Subjects of brain metastasis therapy can participate as long as they are stable (there is no evidence of imaging progress at least 4 weeks before the first dose of trial treatment, and any neurological symptoms have returned to baseline levels), and there are no new or enlarged Evidence of brain metastases in patients, and have not used steroids for at least 7 days before the trial treatment; Suffered from active autoimmune disease in the past 3 months and required systemic treatment, or Documented history of clinically severe autoimmune disease, or syndrome requiring systemic steroids or immunosuppressive agents. Except subjects with vitiligo or childhood asthma/atherosclerosis, subjects who need intermittent bronchodilators or topical steroid injections, and subjects with hypothyroidism and stable to hormone replacement or Sjorgen syndrome; Those who have active viral, bacterial or fungal infections and need treatment (such as pneumonia, etc.); According to the judgment of the investigator, there is a serious harm to the safety of the patient, or affect the completion of the research The accompanying diseases of the study (such as uncontrollable hypertension, uncontrollable diabetes, active interstitial lung disease, etc.); People with allergies, or those who are known to have a history of allergies to the components of this medicine; The baseline pregnancy test of pregnant women, lactating women, or women with childbearing potential is positive; Have a history of immunodeficiency, including HIV test positive, or have other acquired, congenital Sexual immunodeficiency disease, or history of organ transplantation, or allogeneic bone marrow or hematopoietic stem History of cell transplantation; Previously suffering from heart diseases, including: (1) angina pectoris; (2) those requiring clinical intervention Arrhythmia; (3) Myocardial infarction; (4) Heart failure; (5) Other researched Other heart diseases judged to be unsuitable for participating in this trial; Skin basal cell carcinoma and uterine cancer that have been cured of other malignant tumors in the past 5 years Except for cervical carcinoma in situ; People with HBV or HCV infection (defined as HbsAg and/or HbcAb positive and HBV DNA copy number ≥1×104 copy number/ml or ≥2000 IU/ml) or acute or chronic active hepatitis C (HCV) antibodies Positive; Live vaccine has been vaccinated within 30 days before the first dose of treatment