Preheat oven to 450°F. Combine tomato sauce, beans and taco seasoning in medium bowl; set aside.
Cook beef in medium skillet over medium-high heat 5 minutes or until crumbled and no longer pink, stirring occasionally; drain.
Spread sauce mixture over crust. Top evenly with beef and cheese. Place on ungreased pizza pan or baking sheet. Bake 12 to 15 minutes or until crust is browned lightly and cheese melts. Sprinkle with green onions. Cut into 8 slices.