Margaret Atwood is a national heroine in Canada. People follow her on the streest and in stores, seeking autographs and wanting to discuss the characters in her novels - most of whom are intelligent, self-absorbed modern women searching for identity. These women also suffer greatly, and as a result, some Canadian critics have dubbed her ''the high priestess of angst.''

''My women suffer because most of the women I talk to seem to have suffered,'' the 42-year-old Toronto-based author said in a recent interview in New York. ''But you don't hear about it because women's suffering is seen as passive. But there are many owmen who, when facing an ordeal, don't stick their heads in the oven or jump off a bridge. Instead they go out and confront their monster and triumph over it.'' This philosophy has, in part, guided to prolific Miss Atwood in much of her writing (six novels, nine books of poetry and one book of criticism, with a total of about a million copies in print). Her novels regularly make the best-seller lists in Canada, where she is chairman of the 350-member Writers' Union of Canada.

But only in the last few years has she gained major popularity in the United States. During the 1970's she was mainly a literary cult figure, read be a devoted group of fecinists who were taken with the role reversals of her male and female characters. In such acclaimed Atwood novels as ''Surfacing,'' ''Lady Oracle'' and ''Life Before Man,'' women hunt, split logs, make campfires and become successful in their careers, while men often cook and take care of their households.

In her new novel, ''Bodily Harm (Simon & Schester, $14.50), the major character is a young ''life styles'' journalist named Rennie, a woman who writes about such things as ''drain-chain jewelry'' and other such trends. After a portion of Rennie's left breast is removed because of cancer, she loses her lover and then flees Toronto for a vacation on a newly independent Caribbean island. She becomes caught up in a revolution and eventually is imprisoned. But ture to the Atwood style, the suffering herione triumphs and returns to Canada determined to write not about ''life styles'' but about the corrupt regime on the island.