A couple of weeks ago, attorney Helen Trilling moved down with her husband from Boston to join Joseph A. Califano's team at the Department of Health, Education and Welfare.

She started work Monday in an office with a spectacular view of the Capitol and what she now calls a "three-day title" as special assistant to the general counsel.

Trilling had not yet filled the vacant bookshelves and credenza in her office yesterday when her boss got the ax.

Like 225 other top-ranking political appointees serving at the pleasure of the secretary, she worries that she may be out in the cold with Califano in what HEW veterans call one of the biggest political jolts to hit the department in it's quarter-century history.

"It's ulcer time for a lot of these poor people," said June Scanlon Evans, a career employe who has been at HEW since the department was born in 1952. "This is incredible."

Evans has seen all 13 HEW secretaries come and go since Oveta Culp Hobby. "Just when you think you've got everything down pat - the phone number, faces connected with the titles and so on - this happens."

While careers routinely rise and fall with political changes in Washington, a number of HEW employees said they feel this particular change had the air of an ambush from behind.

"No HEW secretary has ever lasted the full four years, but always before they've left voluntarily or because of a change of administration," one veteran said.

Because Califano had assembled a staff with particularly strong loyalties to him and his policies - some of which helped speed his departure - HEW officials fear they will be particularly vulnerable to replacement by incoming secretary Patricia Harris.

Several top Califano aids could not be reached, or declined to be quoted by name because, as one put it, they want to "minimize visibility in order to avoid getting knocked off."

If their presence is not called to Harris' attention, he said, they might be able to stay on in their jobs.

Some speculated that women and blacks might be "safe," because Harris is a black woman. Others are doing quick research on Harris, trying to figure out what she will do.

Officials said they cannot predict how many political appointees would ultimately lose their jobs under Harris, nor how many civil service careerists would be transferred to new spots.

One top Califano aide pointed out that under President Carter's civil service reform act, Harris would have greater flexibility in moving top careerists around.

"This comes at a convenient time in terms of the new Senior Executive Service," he said. "It's a challenge to see it doesn't get perverted ro political purposes."

Several top Califano appointees had only recently uprooted familes and moved households from New York and Massachusetts to Washington.

Others were caught in mid-leap. James B. Bierman was packed up to move next Monday from his private law firm downtown into the department's number two attorney's spot, as deputy general counsel.

"Fortunately, I'm a partner in the firm. I can go back," he said. "I was looking forward to the job, but I think Secretary Harris has the right to pick her own people."

Several hundred HEW employes assembled in the building lobby yesterday to watch television monitors showing Califano's farewell press conference on the other side of the lobby wall.

The crowd cheered and laughed whenever their boss got in a good rhetorical jab at the president.

While many said they had never met Califano and his departure will have no effect on their programs, others were exasperated by Carter's decision.

"This'll just set us back about 18 months in our work," said an executive level welfare specialist.

"Any time you have a change like this, activity slows down. And this comes so late in the administration, it will probably be even more so.

.... Rather than leadership, this seems more like Cronus (in the Greek myth) disemboweling his own children."

Nearby, Lucille Johansen interpreted Califano's speech in sign language for deaf fellow employe Bob Mather. They both work in a program for the handicapped. "I don't see how Califano's leaving will help us do any better," Mather said through his interpreter.

A uniformed building attendant holding an elevator for Califano's passage to and from the press conference, however, said he wouldn't mind seeing Califano go.

"Anybody tries to tell people they can't smoke, man, I don't like that," he said.