NEW YORK (AP) _ Next week, CBS will officially claim its sixth consecutive victory in the prime-time ratings - a testament to its conservative management style, middle- of-the-road programming content and ability to give the public what it seems to want.

The irony is that CBS has a button-down, pinstripe approach to the television business, yet it is the target of hostile takeover talk - from the conservative-backed Fairness in Media, which charged CBS News with alleged liberal news bias, and from media magnate Ted Turner, who filed papers with the Federal Communications Commission today outlining a planned $5 billion bid for CBS.

In its entertainment programming, CBS is the most predictable of the three commercial networks. Dubbed the ''Tiffany Network'' because of the class and sheen of its productions, ''CBS basically does what CBS always does well,'' said Bob Igiel, senior vice president of the NW Ayer advertising agency. ''The CBS shows that seem to work are cast in the CBS mold.''

So CBS will be on top of the 30-week prime-time season when it officially ends Sunday because of its long-running hits, shows like ''Dallas,'' ''60 Minutes'' and ''Simon & Simon.''

Except for innovations in news dating back to the days of Edward R. Murrow, CBS is not generally a TV pioneer in programming. It just seems to do things a little better. For example, CBS was not the first network to try prime-time soap operas, but it found the one that has worked better than any other: ''Dallas.''

Yet CBS's schedule does not have any Emmy Award-dominating series like NBC's ''Hill Street Blues,'' which advanced the cop show form.

''The reason we got to a position of strength is that we took some risks, some prudent risks,'' said Harvey Shephard, senior vice president of CBS Entertainment. Shephard and CBS Entertainment President Bud Grant have been the management team since 1980, what amounts to a generation for this industry.

The operative word is ''prudent.'' CBS's programs appeal to rural, older audiences. Its miniseries ''Space,'' now being broadcast, is doing better in the big cities than in the smaller markets, which is ''a departure from the norm for us,'' said Mike Eisenberg, CBS's director of audience measurement.

CBS was the network that mined hits in the 1960s with ''The Beverly Hillbillies,'' about a dirt-poor Ozark family that struck oil and moved to Beverly Hills, and with ''Green Acres,'' city folks who took over a farm.

Although CBS was No. 1 in total households again, the network has been losing viewers. CBS averaged an 18.1 rating (percentage of the nation's 84.9 million homes watching a given minute of prime time) a year ago, but will wind up with an average rating of about 16.9 for the 1984-85 season.

CBS is also first in total viewers in the lucrative daytime period and in the nightly news, where the ''CBS Evening News'' has been dominant since the mid-1970s.