The purpose of this clinical trial is to evaluate the safety and efficacy of Romiplostim N01 in patients with solid tumors who are undergoing concurrent/sequential radiotherapy and chemotherapy（combined with/without immunotherapy）-related thrombocytopenia.
All eligible patients will be stratified and randomly assigned based on baseline platelet count（Stratification factors: whether the baseline platelet count of the patients is greater than 50×10\^9/L. ） . All patients will be randomly assigned in a 1:1 ratio to experimental group or control group:
Experimental group: Romiplostim N01 (N=53) Control group：Human Interleukin-11(rhlL-11) (N=53) The main questions this trial aims to answer are: 1. The proportion of patients who received platelet transfusion due to thrombocytopenia during the treatment process, as well as the adjustment, delay and discontinuation of radiotherapy and chemotherapy doses； 2. Can patients treated with Romiplostim N01 restore their platelet count to ≥ 100×10\^9/L and what is the response rate of patients during the treatment (response criteria: no need for platelet transfusion and PLT increase ≥ 50×10\^9/L or at least twice the baseline or PLT increase to ≥ 100×10\^9/L)；3. The safety and tolerance of Romiplostim N01 in treating CTIT.