In recent years, the detection rate of thyroid nodules has increased significantly. Different types of thyroid cancer have different survival rates, but most thyroid cancers have a good prognosis. This makes it important to make a definitive diagnosis of malignant nodule as soon as possible. Ultrasound guided fine needle aspiration biopsy (US-FNAB) is the main method for qualitative diagnosis of thyroid nodules before operation. However, its major disadvantage is that the specimen cannot be diagnosed or is unsatisfactory (Bethesda I type). The influencing factors are operator proficiency, nodule characteristics, puncture tools, puncture methods, immediate assessment of specimens, etc. and solutions are repeated puncture, stereotactic three-point and one-line selective puncture method, detection of tumor markers, setting up a biopsy center, on-site visual assessment, thick needle aspiration biopsy, thin layer liquid-based cell smear method.