This is a multi-center, randomized, double blind, placebo-controlled study to evaluate the efficacy, safety, PK, PD and immumogenicity of GR1802 injection in comparison to placebo in patients with atopic dermatitis. Patients will receive GR1802 injection or Placebo every 2 Weeks.

Inclusion Criteria:

1. Diagnosed with AD according to Williams criteria with a history of at least 12 months before Screening, with below requirements: 1) EASI score ≥16 at Screening and Baseline; 2) IGA score ≥3 at Screening and Baseline; 3) ≥10% BSA of AD involvement at Screening and Baseline; 4) Pruritus NRS average score ≥4 at Baseline.
2. Inadequate response or intolerance to topical glucocorticoid therapy for AD within 6 months prior to screening.

Exclusion Criteria:

1. Not enough washing-out period for previous therapy.
2. Concurrent disease/status which may potentially affect the efficacy/safety judgement.
3. Abnormal laboratory test results at screening that, in the judgment of the investigator, may affect the subject's ability to complete the trial.
4. Women who are pregnant or breastfeeding, or planning to become pregnant, breastfeeding during the study.
5. Other