A radiation system is provided. The radiation system may include a bore accommodating an object, a rotary ring, a first radiation source and a second radiation source mounted on the rotary ring and a processor. The first radiation source may be configured to emit a first cone beam toward a first region of the object. The second radiation source may be configured to emit a second beam toward a second region of the object, the second region including at least a part of the first region. The processor may be configured to obtain a treatment plan of the object, the treatment plan including parameters associated with radiation segments. The processor may be further configured to control an emission of the first cone beam and/or the second beam based on the parameters associated with the radiation segments to perform a treatment and a 3-D imaging simultaneously.