When the movie Star Wars premiered in 1977, it was both surprising and a revolution in its special effects.

Is this correct or does it have bad speeling ?

Your spelling is right, but the sentence needs a parallel structure.

When the movie Star Wars premiered in 1977, it was both surprising and revolutionary in its special effects.

corret

The sentence you provided is mostly correct, but it does have a typo. The word "spelling" is misspelled as "speeling." However, the rest of the sentence is accurate and conveys the intended meaning. If you want to correct the spelling error, you can simply change "speeling" to "special effects." The revised sentence would then read: "When the movie Star Wars premiered in 1977, it was both surprising and a revolution in its special effects."