I found a lot of tutorials, but none of them worked for me. After many comparison tests, I found that the problem lies in a small space!
Look at your .bib file, as follows, check whether there is a space in the first line, if so, delete the space (note that you need to compile twice, it is best to delete the two process files .aux.bbl); if not, then you Or look for other tutorials.
I started using the bibtex exported by Wanfang, and there will be spaces! ! ! pit! ! !
@article{
杨秋菊2011基于改进Canny特征点的SIFT算法,%看这里是不是有空格
author={
杨秋菊 and 肖雪梅},
title={
基于改进Canny特征点的SIFT算法},
journal={
计算机工程与设计},
year={
2011},
volume={
32},
number={
7},
pages={
2428-2431,2458},
month={
12},
}