The aim of this study was to explore the application value of paravertebral nerve block (PVB) based on goaloriented nano-liquid in patients undergoing thoracotomy. In this study, ordinary starch granules were applied to prepare starch nano-spheres by reverse phase suspension cross-linking polymerization. Then, there is an analysis on the influence of pH value, stirring speed, and reaction time on the particle size and swelling degree of starch nano-spheres. The infrared spectroscopy, scanning electron microscope, X-ray diffraction, and laser particle size were employed to analyze the particle size, characterization, and structure of starch and nanostarch microspheres in turn. 102 patients with lung cancer undergoing elective thoracotomy were selected as the research objects and rolled into a PVB group (group A) and a goal-oriented nano-liquid combined PVB (group B). The heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), cardiac output index (CI), and cardiac output (CO) changes of patients from the two groups were observed at each time point. The changes of VAS scores for pain in patients from the two groups were analyzed at quietness and cough at the 3rd hour and 6th hour after surgery, as well as the incidence of postoperative complications. The results showed that when pH = 9, rotation speed was 1,000 rpm/min, and reaction time was 1 hour, the particle size of starch nano-particles was the smallest (260.74±8.78 nm), which were spherical, and the vibration absorption peak of glycosidic bond C–O–C was about 1,000 cm−1. Moreover, there were obvious diffraction peaks at 15°, 17°, and 24°. At T1, T2, and T4, the MAP value of patients from group A was dramatically higher than the value of group B (P < 0.05), and the HR value of patients in group A was also greatly higher than that of group B at T3, T2, and T1 (P < 0.05). The VAS scores of patients from group A at quietness and cough at the 6th hour after surgery increased greatly in contrast to the scores of group B (P < 0.05). In addition, the proportion of patients in group A with postoperative complications of hypertension, chills, restlessness, and delayed recovery was markedly higher than that of group B (P < 0.05). It indicated that the goal-oriented nano-starch liquid combined with PVB had little influence on the hemodynamics of patients undergoing thoracotomy, and the postoperative VAS scores and complications were reduced.